diff --git a/gnu/packages/admin.scm b/gnu/packages/admin.scm
index 586ec98c1c..2933c6a370 100644
--- a/gnu/packages/admin.scm
+++ b/gnu/packages/admin.scm
@@ -2694,7 +2694,7 @@ (define (python-path dir)
                  "install-nping")
                (make ndiff "install-ndiff")
                (wrap-program (string-append ndiff "/bin/ndiff")
-                 `("PYTHONPATH" prefix
+                 `("GUIX_PYTHONPATH" prefix
                    (,(python-path ndiff)))))
              #t))
          ;; These are the tests that do not require network access.
@@ -2749,7 +2749,7 @@ (define-public dstat
            (lambda* (#:key outputs #:allow-other-keys)
              (let ((out (assoc-ref outputs "out")))
                (wrap-program (string-append out "/bin/dstat")
-                 `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH"))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH"))))
                #t))))))
     (inputs
      `(("python" ,python-wrapper)
diff --git a/gnu/packages/audio.scm b/gnu/packages/audio.scm
index 6fe441faae..90b3c49873 100644
--- a/gnu/packages/audio.scm
+++ b/gnu/packages/audio.scm
@@ -2023,9 +2023,9 @@ (define-public jack-2
            (lambda* (#:key inputs outputs #:allow-other-keys)
              ;; Make sure 'jack_control' runs with the correct PYTHONPATH.
              (let* ((out (assoc-ref outputs "out"))
-                    (path (getenv "PYTHONPATH")))
+                    (path (getenv "GUIX_PYTHONPATH")))
                (wrap-program (string-append out "/bin/jack_control")
-                 `("PYTHONPATH" ":" prefix (,path))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,path))))
              #t)))))
     (inputs
      `(("alsa-lib" ,alsa-lib)
@@ -4579,7 +4579,7 @@ (define-public carla
            (lambda* (#:key outputs #:allow-other-keys)
              (let ((out (assoc-ref outputs "out")))
                (wrap-script (string-append out "/bin/carla")
-                            `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH"))))
+                            `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH"))))
                #t))))))
     (inputs
      `(("alsa-lib" ,alsa-lib)
diff --git a/gnu/packages/benchmark.scm b/gnu/packages/benchmark.scm
index 3470f3860b..6c04b23f43 100644
--- a/gnu/packages/benchmark.scm
+++ b/gnu/packages/benchmark.scm
@@ -103,7 +103,7 @@ (define-public fio
                            "fiologparser.py"))
                ;; Make sure numpy et.al is found.
                (wrap-program (string-append newbin "/fiologparser_hist.py")
-                 `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH"))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH"))))
                #t))))))
     (outputs '("out" "utils"))
     (inputs
diff --git a/gnu/packages/bioinformatics.scm b/gnu/packages/bioinformatics.scm
index a6eda0c280..86270ecc75 100644
--- a/gnu/packages/bioinformatics.scm
+++ b/gnu/packages/bioinformatics.scm
@@ -2263,9 +2263,9 @@ (define-public couger
           (lambda* (#:key inputs outputs #:allow-other-keys)
             ;; Make sure 'couger' runs with the correct PYTHONPATH.
             (let* ((out (assoc-ref outputs "out"))
-                   (path (getenv "PYTHONPATH")))
+                   (path (getenv "GUIX_PYTHONPATH")))
               (wrap-program (string-append out "/bin/couger")
-                `("PYTHONPATH" ":" prefix (,path))))
+                `("GUIX_PYTHONPATH" ":" prefix (,path))))
             #t)))))
     (inputs
      `(("python" ,python-2)
@@ -10696,7 +10696,7 @@ (define-public gess
 " line)))
                ;; Make sure GESS has all modules in its path
                (wrap-script (string-append target "GESS.py")
-                 `("PYTHONPATH" ":" = (,target ,(getenv "PYTHONPATH"))))
+                 `("GUIX_PYTHONPATH" ":" = (,target ,(getenv "GUIX_PYTHONPATH"))))
                (mkdir-p bin)
                (symlink (string-append target "GESS.py")
                         (string-append bin "GESS.py"))
@@ -12871,11 +12871,11 @@ (define-public find-circ
              (lambda* (#:key outputs #:allow-other-keys)
                (let* ((out (assoc-ref outputs "out"))
                       (bin (string-append out "/bin"))
-                      (path (getenv "PYTHONPATH")))
+                      (path (getenv "GUIX_PYTHONPATH")))
                  (for-each (lambda (script)
                              (install-file script bin)
                              (wrap-program (string-append bin "/" script)
-                               `("PYTHONPATH" ":" prefix (,path))))
+                               `("GUIX_PYTHONPATH" ":" prefix (,path))))
                            '("cmp_bed.py"
                              "find_circ.py"
                              "maxlength.py"
@@ -13817,10 +13817,10 @@ (define-public filtlong
            (add-after 'install 'wrap-program
              (lambda* (#:key inputs outputs #:allow-other-keys)
                (let* ((out (assoc-ref outputs "out"))
-                      (path (getenv "PYTHONPATH")))
+                      (path (getenv "GUIX_PYTHONPATH")))
                  (wrap-program (string-append out
                                               "/share/filtlong/scripts/histogram.py")
-                   `("PYTHONPATH" ":" prefix (,path))))
+                   `("GUIX_PYTHONPATH" ":" prefix (,path))))
                #t))
            (add-before 'check 'patch-tests
              (lambda _
@@ -13894,7 +13894,7 @@ (define-public nanopolish
            (add-after 'install 'wrap-programs
              (lambda* (#:key outputs #:allow-other-keys)
                (for-each (lambda (file)
-                           (wrap-program file `("PYTHONPATH" ":" prefix (,path))))
+                           (wrap-program file `("GUIX_PYTHONPATH" ":" prefix (,path))))
                          (find-files "/share/nanopolish/scripts" "\\.py"))
                (for-each (lambda (file)
                            (wrap-program file `("PERL5LIB" ":" prefix (,path))))
diff --git a/gnu/packages/cdrom.scm b/gnu/packages/cdrom.scm
index a8da7ba48b..b2d593d823 100644
--- a/gnu/packages/cdrom.scm
+++ b/gnu/packages/cdrom.scm
@@ -1039,7 +1039,7 @@ (define-public cdemu-client
              (let ((prog (string-append (assoc-ref outputs "out")
                                         "/bin/cdemu")))
                (wrap-program prog
-                 `("PYTHONPATH" = (,(getenv "PYTHONPATH"))))
+                 `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH"))))
                #t))))))
     (home-page "https://cdemu.sourceforge.io/")
     (synopsis "Command-line client for controlling cdemu-daemon")
diff --git a/gnu/packages/chemistry.scm b/gnu/packages/chemistry.scm
index ddbf5ca098..0fef6a7ff3 100644
--- a/gnu/packages/chemistry.scm
+++ b/gnu/packages/chemistry.scm
@@ -107,9 +107,9 @@ (define-public avogadro
                         ,(version-major+minor
                            (package-version python))
                         "/site-packages:"
-                        (getenv "PYTHONPATH")))
+                        (getenv "GUIX_PYTHONPATH")))
                (wrap-program (string-append out "/bin/avogadro")
-                 `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH")))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH")))))
              #t)))))
     (native-inputs
      `(("doxygen" ,doxygen)
diff --git a/gnu/packages/connman.scm b/gnu/packages/connman.scm
index 5f17a0ea95..11b9d4ec5c 100644
--- a/gnu/packages/connman.scm
+++ b/gnu/packages/connman.scm
@@ -121,7 +121,7 @@ (define-public econnman
              (let* ((out (assoc-ref outputs "out"))
                     (bin (string-append out "/bin/econnman-bin")))
                (wrap-program bin
-                 `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH"))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH"))))
                #t))))))
     (native-inputs `(("pkg-config" ,pkg-config)))
     (inputs
diff --git a/gnu/packages/cups.scm b/gnu/packages/cups.scm
index f2b78e352e..9b00fe1cf9 100644
--- a/gnu/packages/cups.scm
+++ b/gnu/packages/cups.scm
@@ -581,7 +581,7 @@ (define-public hplip
                                             out "/lib/python"
                                             (python:python-version python)
                                             "/site-packages")
-                                           (getenv "PYTHONPATH")
+                                           (getenv "GUIX_PYTHONPATH")
                                            bin target)))
                                (chmod file #o755)))
                   (find-files "." (lambda (file stat)
diff --git a/gnu/packages/debug.scm b/gnu/packages/debug.scm
index b3a000e6e3..2913c348f3 100644
--- a/gnu/packages/debug.scm
+++ b/gnu/packages/debug.scm
@@ -510,10 +510,10 @@ (define-public scanmem
            (lambda* (#:key inputs outputs #:allow-other-keys)
              (let ((out               (assoc-ref outputs "out"))
                    (gi-typelib-path   (getenv "GI_TYPELIB_PATH"))
-                   (python-path       (getenv "PYTHONPATH")))
+                   (python-path       (getenv "GUIX_PYTHONPATH")))
                (wrap-program (string-append out "/share/gameconqueror/GameConqueror.py")
                  `("GI_TYPELIB_PATH"        ":" prefix (,gi-typelib-path))
-                 `("PYTHONPATH"             ":" prefix (,python-path))))
+                 `("GUIX_PYTHONPATH"             ":" prefix (,python-path))))
              #t)))))
     (native-inputs
      `(("libtool" ,libtool)
diff --git a/gnu/packages/display-managers.scm b/gnu/packages/display-managers.scm
index b6e5ab7d19..a6a1c97360 100644
--- a/gnu/packages/display-managers.scm
+++ b/gnu/packages/display-managers.scm
@@ -192,7 +192,7 @@ (define-public lightdm
            ;; Run test-suite under a dbus session.
            (lambda* (#:key inputs #:allow-other-keys)
              (wrap-program "tests/src/test-python-greeter"
-               `("PYTHONPATH"      ":" prefix (,(getenv "PYTHONPATH")))
+               `("GUIX_PYTHONPATH"      ":" prefix (,(getenv "GUIX_PYTHONPATH")))
                `("GI_TYPELIB_PATH" ":" prefix (,(getenv "GI_TYPELIB_PATH"))))
 
              ;; Avoid printing locale warnings, which trip up the text
diff --git a/gnu/packages/ebook.scm b/gnu/packages/ebook.scm
index 47bbd1a789..34a04e505c 100644
--- a/gnu/packages/ebook.scm
+++ b/gnu/packages/ebook.scm
@@ -482,12 +482,12 @@ (define-public cozy
                     (libmagic-path     (string-append
                                         (assoc-ref %build-inputs "file")
                                         "/lib"))
-                    (python-path     (getenv "PYTHONPATH")))
+                    (python-path     (getenv "GUIX_PYTHONPATH")))
                (wrap-program (string-append out "/bin/cozy")
                  `("LD_LIBRARY_PATH" ":" prefix (,libmagic-path))
                  `("GI_TYPELIB_PATH" ":" prefix (,gi-typelib-path))
                  `("GST_PLUGIN_SYSTEM_PATH" ":" prefix (,gst-plugin-path))
-                 `("PYTHONPATH" ":" prefix (,python-path ,pylib))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,python-path ,pylib))))
              #t)))))
     (native-inputs
      `(("desktop-file-utils" ,desktop-file-utils)
diff --git a/gnu/packages/education.scm b/gnu/packages/education.scm
index 07862291a7..3ffc789bb9 100644
--- a/gnu/packages/education.scm
+++ b/gnu/packages/education.scm
@@ -798,7 +798,7 @@ (define-public anki
                              `("PATH" prefix (,(string-append
                                                 (assoc-ref inputs "mpv")
                                                 "/bin")))
-                             `("PYTHONPATH" = ,site-packages)))
+                             `("GUIX_PYTHONPATH" = ,site-packages)))
                          (find-files bin ".")))
              #t)))))
     (native-inputs
diff --git a/gnu/packages/engineering.scm b/gnu/packages/engineering.scm
index 7928b4d06f..c9e90c4f5b 100644
--- a/gnu/packages/engineering.scm
+++ b/gnu/packages/engineering.scm
@@ -929,9 +929,9 @@ (define-public kicad
                            ,(version-major+minor
                              (package-version python))
                            "/site-packages:"
-                           (getenv "PYTHONPATH"))))
+                           (getenv "GUIX_PYTHONPATH"))))
                (wrap-program file
-                 `("PYTHONPATH" ":" prefix (,path))
+                 `("GUIX_PYTHONPATH" ":" prefix (,path))
                  `("PATH" ":" prefix
                    (,(string-append python "/bin:")))))
              #t)))))
@@ -1192,9 +1192,9 @@ (define-public volk
                            ,(version-major+minor
                              (package-version python))
                            "/site-packages:"
-                           (getenv "PYTHONPATH"))))
+                           (getenv "GUIX_PYTHONPATH"))))
                (wrap-program file
-                 `("PYTHONPATH" ":" prefix (,path))
+                 `("GUIX_PYTHONPATH" ":" prefix (,path))
                  `("PATH" ":" prefix
                    (,(string-append python "/bin:")))))
              #t)))))
@@ -2601,7 +2601,7 @@ (define-public freecad
                (let ((out (assoc-ref outputs "out")))
                  (wrap-program (string-append out "/bin/FreeCAD")
                    (list "PYTHONPATH"
-                         'prefix (list (getenv "PYTHONPATH")))))
+                         'prefix (list (getenv "GUIX_PYTHONPATH")))))
                #t)))))
       (home-page "https://www.freecadweb.org/")
       (synopsis "Your Own 3D Parametric Modeler")
diff --git a/gnu/packages/game-development.scm b/gnu/packages/game-development.scm
index fa7875d077..58c397ebc5 100644
--- a/gnu/packages/game-development.scm
+++ b/gnu/packages/game-development.scm
@@ -1377,7 +1377,7 @@ (define* (install-renpy-game #:key output game name (renpy renpy)
            (lambda* (#:key inputs outputs #:allow-other-keys)
              (wrap-program (string-append (assoc-ref outputs "out")
                                           "/bin/renpy")
-               `("PYTHONPATH" = (,(getenv "PYTHONPATH"))))
+               `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH"))))
              #t)))))
     (inputs
      `(("python2-tkinter" ,python-2 "tk")
diff --git a/gnu/packages/games.scm b/gnu/packages/games.scm
index b059c52d07..de018cb4c0 100644
--- a/gnu/packages/games.scm
+++ b/gnu/packages/games.scm
@@ -2102,7 +2102,7 @@ (define-public roguebox-adventures
 #!~a
 export PYTHONPATH=~a/LIB:~a
 exec -a \"~a\" ~a \"$@\"\n"
-                           (which "bash") data (getenv "PYTHONPATH")
+                           (which "bash") data (getenv "GUIX_PYTHONPATH")
                            (which "python3")
                            (string-append lib "/main.py"))))
                (chmod roguebox-adventures #o555))
@@ -2178,7 +2178,7 @@ (define-public seahorse-adventures
                              "#!~a~@
                               export PYTHONPATH=~a:~a~@
                               exec -a \"~a\" ~a \"$@\"~%"
-                             (which "bash") data (getenv "PYTHONPATH")
+                             (which "bash") data (getenv "GUIX_PYTHONPATH")
                              (which "python3")
                              (string-append data "/run_game.py"))))
                  (chmod executable #o555))
@@ -10118,7 +10118,7 @@ (define-public kajongg
            (lambda* (#:key outputs #:allow-other-keys)
              (let ((out (assoc-ref outputs "out")))
                (wrap-program (string-append out "/bin/kajongg")
-                 `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH"))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH"))))
                #t))))))
     (native-inputs
      `(("extra-cmake-modules" ,extra-cmake-modules)
diff --git a/gnu/packages/gimp.scm b/gnu/packages/gimp.scm
index 4d229a1fd9..fc8e0098bb 100644
--- a/gnu/packages/gimp.scm
+++ b/gnu/packages/gimp.scm
@@ -300,7 +300,7 @@ (define-public gimp
            ;; Install 'sitecustomize.py' into gimp's python directory to
            ;; add pygobject and pygtk to pygimp's search path.
            (lambda* (#:key outputs #:allow-other-keys)
-             (let* ((pythonpath (getenv "PYTHONPATH"))
+             (let* ((pythonpath (getenv "GUIX_PYTHONPATH"))
                     (out        (assoc-ref outputs "out"))
                     (sitecustomize.py
                      (string-append
@@ -579,7 +579,7 @@ (define-public glimpse
            ;; Install 'sitecustomize.py' into glimpse's python directory to
            ;; add pygobject and pygtk to pygimp's search path.
            (lambda* (#:key outputs #:allow-other-keys)
-             (let* ((pythonpath (getenv "PYTHONPATH"))
+             (let* ((pythonpath (getenv "GUIX_PYTHONPATH"))
                     (out        (assoc-ref outputs "out"))
                     (sitecustomize.py
                      (string-append
diff --git a/gnu/packages/glib.scm b/gnu/packages/glib.scm
index b6e4b8844b..fdbe6d0cdf 100644
--- a/gnu/packages/glib.scm
+++ b/gnu/packages/glib.scm
@@ -553,7 +553,7 @@ (define itstool
              (let ((prog (string-append (assoc-ref outputs "out")
                                         "/bin/itstool")))
                (wrap-program prog
-                 `("PYTHONPATH" = (,(getenv "PYTHONPATH"))))
+                 `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH"))))
                #t))))))
     (home-page "http://www.itstool.org")
     (synopsis "Tool to translate XML documents with PO files")
diff --git a/gnu/packages/gnome.scm b/gnu/packages/gnome.scm
index 3399b5ae7d..1b8ada642c 100644
--- a/gnu/packages/gnome.scm
+++ b/gnu/packages/gnome.scm
@@ -895,7 +895,7 @@ (define-public gnome-music
                  `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH")))
                  `("GST_PLUGIN_SYSTEM_PATH" = (,(getenv "GST_PLUGIN_SYSTEM_PATH")))
                  `("GRL_PLUGIN_PATH" = (,(getenv "GRL_PLUGIN_PATH")))
-                 `("PYTHONPATH" = (,(getenv "PYTHONPATH") ,pylib))))
+                 `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH") ,pylib))))
              #t)))))
     (native-inputs
      `(("desktop-file-utils" ,desktop-file-utils)
@@ -2670,7 +2670,7 @@ (define-public gtg
                                            (package-version python))
                                          "/site-packages")))
                (wrap-program prog
-                 `("PYTHONPATH" = (,(getenv "PYTHONPATH") ,pylib))
+                 `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH") ,pylib))
                  `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH"))))
                #t))))))
     (native-inputs
@@ -6174,12 +6174,12 @@ (define-public rhythmbox
                  (gi-typelib-path   (getenv "GI_TYPELIB_PATH"))
                  (gst-plugin-path   (getenv "GST_PLUGIN_SYSTEM_PATH"))
                  (grl-plugin-path   (getenv "GRL_PLUGIN_PATH"))
-                 (python-path       (getenv "PYTHONPATH")))
+                 (python-path       (getenv "GUIX_PYTHONPATH")))
              (wrap-program (string-append out "/bin/rhythmbox")
                `("GI_TYPELIB_PATH"        ":" prefix (,gi-typelib-path))
                `("GST_PLUGIN_SYSTEM_PATH" ":" prefix (,gst-plugin-path))
                `("GRL_PLUGIN_PATH"        ":" prefix (,grl-plugin-path))
-               `("PYTHONPATH"             ":" prefix (,python-path))))
+               `("GUIX_PYTHONPATH"             ":" prefix (,python-path))))
            #t)))))
    (propagated-inputs
     `(("dconf" ,dconf)))
@@ -6547,7 +6547,7 @@ (define-public eolie
                            ":")))
                (wrap-program (string-append out "/bin/eolie")
                  `("LD_LIBRARY_PATH" ":" prefix (,path))
-                 `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH")))
+                 `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH")))
                  `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH")))))
              #t)))))
     (native-inputs
@@ -6691,7 +6691,7 @@ (define-public d-feet
             (let ((prog (string-append (assoc-ref outputs "out")
                                        "/bin/d-feet")))
               (wrap-program prog
-                `("PYTHONPATH" = (,(getenv "PYTHONPATH")))
+                `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH")))
                 `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH"))))
               #t))))))
     (native-inputs
@@ -7150,11 +7150,11 @@ (define-public gedit
              (let ((out               (assoc-ref outputs "out"))
                    (gtksourceview     (assoc-ref inputs "gtksourceview"))
                    (gi-typelib-path   (getenv "GI_TYPELIB_PATH"))
-                   (python-path       (getenv "PYTHONPATH")))
+                   (python-path       (getenv "GUIX_PYTHONPATH")))
                (wrap-program (string-append out "/bin/gedit")
                  ;; For plugins.
                  `("GI_TYPELIB_PATH" ":" prefix (,gi-typelib-path))
-                 `("PYTHONPATH" ":" prefix (,python-path))
+                 `("GUIX_PYTHONPATH" ":" prefix (,python-path))
                  ;; For language-specs.
                  `("XDG_DATA_DIRS" ":" prefix (,(string-append gtksourceview
                                                                "/share")))))
@@ -7515,12 +7515,12 @@ (define-public caribou
          (add-after 'install 'wrap-programs
           (lambda* (#:key outputs #:allow-other-keys)
             (let* ((out (assoc-ref outputs "out"))
-                   (python-path (getenv "PYTHONPATH"))
+                   (python-path (getenv "GUIX_PYTHONPATH"))
                    (gi-typelib-path (getenv "GI_TYPELIB_PATH")))
               (for-each
                (lambda (prog)
                  (wrap-program prog
-                   `("PYTHONPATH"      ":" prefix (,python-path))
+                   `("GUIX_PYTHONPATH"      ":" prefix (,python-path))
                    `("GI_TYPELIB_PATH" ":" prefix (,gi-typelib-path))))
                (list (string-append out "/bin/caribou-preferences")
                      (string-append out "/libexec/antler-keyboard"))))
@@ -8422,7 +8422,7 @@ (define-public gnome-shell
            (lambda* (#:key inputs outputs #:allow-other-keys)
              (let ((out              (assoc-ref outputs "out"))
                    (gi-typelib-path  (getenv "GI_TYPELIB_PATH"))
-                   (python-path      (getenv "PYTHONPATH")))
+                   (python-path      (getenv "GUIX_PYTHONPATH")))
                (wrap-program (string-append out "/bin/gnome-shell")
                  `("GI_TYPELIB_PATH" ":" prefix (,gi-typelib-path))
                  ;; FIXME: gnome-shell loads these libraries with unqualified
@@ -8436,7 +8436,7 @@ (define-public gnome-shell
                (for-each
                 (lambda (prog)
                   (wrap-program (string-append out "/bin/" prog)
-                    `("PYTHONPATH"      ":" prefix (,python-path))
+                    `("GUIX_PYTHONPATH"      ":" prefix (,python-path))
                     `("GI_TYPELIB_PATH" ":" prefix (,gi-typelib-path))))
                 '("gnome-shell-extension-tool" "gnome-shell-perf-tool"))
                #t)))
@@ -9217,7 +9217,7 @@ (define-public authenticator
                                            (package-version python))
                                          "/site-packages")))
                (wrap-program prog
-                 `("PYTHONPATH" = (,(getenv "PYTHONPATH") ,pylib))
+                 `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH") ,pylib))
                  `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH"))))
                #t))))))
     (native-inputs
@@ -9428,13 +9428,13 @@ (define-public gnome-todo
                     (lambda* (#:key inputs outputs #:allow-other-keys)
                       (let ((out               (assoc-ref outputs "out"))
                             (gi-typelib-path   (getenv "GI_TYPELIB_PATH"))
-                            (python-path       (getenv "PYTHONPATH")))
+                            (python-path       (getenv "GUIX_PYTHONPATH")))
                         (wrap-program (string-append out "/bin/gnome-todo")
                           ;; XXX: gi plugins are broken.
                           ;; See https://bugzilla.gnome.org/show_bug.cgi?id=787212
                           ;; For plugins.
                           `("GI_TYPELIB_PATH" ":" prefix (,gi-typelib-path))
-                          `("PYTHONPATH" ":" prefix (,python-path))))
+                          `("GUIX_PYTHONPATH" ":" prefix (,python-path))))
                       #t)))))
     (native-inputs
      `(("gettext" ,gettext-minimal)
@@ -10037,8 +10037,8 @@ (define-public orca
                    (,(getenv "GI_TYPELIB_PATH")))
                  `("GST_PLUGIN_SYSTEM_PATH" ":" prefix
                    (,(getenv "GST_PLUGIN_SYSTEM_PATH")))
-                 `("PYTHONPATH" ":" prefix
-                   (,(getenv "PYTHONPATH")))))
+                 `("GUIX_PYTHONPATH" ":" prefix
+                   (,(getenv "GUIX_PYTHONPATH")))))
              #t)))))
     (native-inputs
      `(("intltool" ,intltool)
@@ -10370,7 +10370,7 @@ (define-public passwordsafe
                                            (package-version python))
                                          "/site-packages")))
                (wrap-program prog
-                 `("PYTHONPATH" = (,(getenv "PYTHONPATH") ,pylib))
+                 `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH") ,pylib))
                  `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH"))))
                #t))))))
     (native-inputs
@@ -10790,7 +10790,7 @@ (define-public terminator
                                           (package-version python))
                                         "/site-packages")))
               (wrap-program prog
-                `("PYTHONPATH" = (,(getenv "PYTHONPATH") ,pylib))
+                `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH") ,pylib))
                 `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH"))))
               #t)))
          (add-after 'wrap-program 'glib-or-gtk-wrap
@@ -11423,7 +11423,7 @@ (define-public setzer
                                            (package-version python))
                                          "/site-packages")))
                (wrap-program prog
-                 `("PYTHONPATH" = (,(getenv "PYTHONPATH") ,pylib))
+                 `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH") ,pylib))
                  `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH"))))
                #t))))))
     (native-inputs
@@ -11483,7 +11483,7 @@ (define-public libratbag
                     (pygo (string-append
                            (assoc-ref inputs "python-pygobject") site))
                     (python-wrap
-                     `("PYTHONPATH" = (,evdev ,pygo))))
+                     `("GUIX_PYTHONPATH" = (,evdev ,pygo))))
                (wrap-program (string-append out "/bin/" "ratbagctl")
                  python-wrap)
                #t))))))
@@ -11865,7 +11865,7 @@ (define-public komikku
             (let ((prog (string-append (assoc-ref outputs "out")
                                        "/bin/komikku")))
               (wrap-program prog
-                `("PYTHONPATH" = (,(getenv "PYTHONPATH")))
+                `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH")))
                 `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH"))))
               #t))))))
     (inputs
diff --git a/gnu/packages/gps.scm b/gnu/packages/gps.scm
index 4fa3bcef19..7f047aa6ba 100644
--- a/gnu/packages/gps.scm
+++ b/gnu/packages/gps.scm
@@ -280,7 +280,7 @@ (define-public gpsd
                                              ":")))
                (for-each (lambda (script)
                            (wrap-program (string-append out "/bin/" script)
-                             `("PYTHONPATH" ":" prefix (,pythonpath))))
+                             `("GUIX_PYTHONPATH" ":" prefix (,pythonpath))))
                          '("gegps" "gpscat" "gpsfake" "gpsprof"
                            "ubxtool" "xgps" "xgpsspeed" "zerk")))
              #t)))))
diff --git a/gnu/packages/gtk.scm b/gnu/packages/gtk.scm
index 6a35e325e5..384ee608d3 100644
--- a/gnu/packages/gtk.scm
+++ b/gnu/packages/gtk.scm
@@ -1766,7 +1766,7 @@ (define-public gtk-doc
              (let ((out (assoc-ref outputs "out")))
                (for-each (lambda (prog)
                            (wrap-program prog
-                             `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH")))))
+                             `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH")))))
                          (find-files (string-append out "/bin")))
                #t))))
        #:configure-flags
diff --git a/gnu/packages/ibus.scm b/gnu/packages/ibus.scm
index 9e13f8643b..1ce826d65e 100644
--- a/gnu/packages/ibus.scm
+++ b/gnu/packages/ibus.scm
@@ -130,7 +130,7 @@ (define-public ibus
              ;; GI_TYPELIB_PATH.
              (let ((out (assoc-ref outputs "out")))
                (wrap-program (string-append out "/bin/ibus-setup")
-                 `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH")))
+                 `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH")))
                  `("GI_TYPELIB_PATH" ":" prefix
                    (,(getenv "GI_TYPELIB_PATH")
                     ,(string-append out "/lib/girepository-1.0")))))
@@ -192,8 +192,8 @@ (define-public ibus-libpinyin
              ;; PYTHONPATH and GI_TYPELIB_PATH.
              (let ((out (assoc-ref outputs "out")))
                (wrap-program (string-append out "/libexec/ibus-setup-libpinyin")
-                 `("PYTHONPATH" ":" prefix
-                   (,(getenv "PYTHONPATH")
+                 `("GUIX_PYTHONPATH" ":" prefix
+                   (,(getenv "GUIX_PYTHONPATH")
                     ,(string-append (assoc-ref inputs "ibus")
                                     "/lib/girepository-1.0")))
                  `("GI_TYPELIB_PATH" ":" prefix
@@ -270,8 +270,8 @@ (define-public ibus-anthy
                (for-each
                 (lambda (prog)
                   (wrap-program (string-append out "/libexec/" prog)
-                    `("PYTHONPATH" ":" prefix
-                      (,(getenv "PYTHONPATH")))
+                    `("GUIX_PYTHONPATH" ":" prefix
+                      (,(getenv "GUIX_PYTHONPATH")))
                     `("GI_TYPELIB_PATH" ":" prefix
                       (,(getenv "GI_TYPELIB_PATH")
                        ,(string-append out "/lib/girepository-1.0")))))
@@ -733,7 +733,7 @@ (define-public ibus-libhangul
            (lambda* (#:key inputs outputs #:allow-other-keys)
              (wrap-program (string-append (assoc-ref outputs "out")
                                           "/libexec/ibus-setup-hangul")
-               `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH")))
+               `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH")))
                `("LD_LIBRARY_PATH" ":" prefix
                  (,(string-append (assoc-ref inputs "libhangul") "/lib")))
                `("GI_TYPELIB_PATH" ":" prefix
diff --git a/gnu/packages/inkscape.scm b/gnu/packages/inkscape.scm
index 48dc46ed10..e9cdb16f00 100644
--- a/gnu/packages/inkscape.scm
+++ b/gnu/packages/inkscape.scm
@@ -258,7 +258,7 @@ (define-public inkscape-1.0
            (lambda* (#:key outputs #:allow-other-keys)
              (let ((out (assoc-ref outputs "out")))
                (wrap-program (string-append out "/bin/inkscape")
-                 `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH")))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH")))))
              #t)))))
     (inputs
      `(("aspell" ,aspell)
diff --git a/gnu/packages/linux.scm b/gnu/packages/linux.scm
index 2e7230ceff..db67feafe5 100644
--- a/gnu/packages/linux.scm
+++ b/gnu/packages/linux.scm
@@ -7701,7 +7701,7 @@ (define-public bcc
                 (lambda (python-executable)
                   (format #t "Wrapping: ~A.~%" python-executable)
                   (wrap-program python-executable
-                    `("PYTHONPATH" ":" prefix
+                    `("GUIX_PYTHONPATH" ":" prefix
                       (,(string-append lib
                                        "/python"
                                        ,(version-major+minor
diff --git a/gnu/packages/machine-learning.scm b/gnu/packages/machine-learning.scm
index 7a77897b25..59a422211b 100644
--- a/gnu/packages/machine-learning.scm
+++ b/gnu/packages/machine-learning.scm
@@ -1372,7 +1372,7 @@ (define-public kaldi-gstreamer-server
                  (let* ((server (string-append bin "/kaldi-gst-server"))
                         (client (string-append bin "/kaldi-gst-client"))
                         (worker (string-append bin "/kaldi-gst-worker"))
-                        (PYTHONPATH (getenv "PYTHONPATH"))
+                        (PYTHONPATH (getenv "GUIX_PYTHONPATH"))
                         (GST_PLUGIN_PATH (string-append
                                           (assoc-ref inputs "gst-kaldi-nnet2-online")
                                           "/lib/gstreamer-1.0:${GST_PLUGIN_PATH}"))
diff --git a/gnu/packages/mail.scm b/gnu/packages/mail.scm
index 9756a36329..b55b0d3321 100644
--- a/gnu/packages/mail.scm
+++ b/gnu/packages/mail.scm
@@ -1231,7 +1231,7 @@ (define-public notifymuch
                (let* ((out (assoc-ref outputs "out"))
                       (bin (string-append out "/bin/notifymuch")))
                  (wrap-program bin
-                   `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH")))
+                   `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH")))
                    `("GI_TYPELIB_PATH" ":" prefix
                      (,(getenv "GI_TYPELIB_PATH")
                       ,(string-append out "/lib/girepository-1.0")))))
diff --git a/gnu/packages/maths.scm b/gnu/packages/maths.scm
index d46cca8f3a..36b165cc13 100644
--- a/gnu/packages/maths.scm
+++ b/gnu/packages/maths.scm
@@ -326,8 +326,8 @@ (define-public units
                      (let* ((out (assoc-ref outputs "out"))
                             (bin (string-append out "/bin")))
                        (wrap-program (string-append bin "/units_cur")
-                         `("PYTHONPATH" ":" prefix
-                           ,(search-path-as-string->list (getenv "PYTHONPATH"))))
+                         `("GUIX_PYTHONPATH" ":" prefix
+                           ,(search-path-as-string->list (getenv "GUIX_PYTHONPATH"))))
                        #t))))))
    (synopsis "Conversion between thousands of scales")
    (description
diff --git a/gnu/packages/mpd.scm b/gnu/packages/mpd.scm
index 6066913f16..d5811cc273 100644
--- a/gnu/packages/mpd.scm
+++ b/gnu/packages/mpd.scm
@@ -401,9 +401,9 @@ (define-public mpdris2
          (add-after 'install 'wrap-program
            (lambda* (#:key inputs outputs #:allow-other-keys)
              (let ((out         (assoc-ref outputs "out"))
-                   (python-path (getenv "PYTHONPATH")))
+                   (python-path (getenv "GUIX_PYTHONPATH")))
                (wrap-program (string-append out "/bin/mpDris2")
-                 `("PYTHONPATH" ":" prefix (,python-path)))
+                 `("GUIX_PYTHONPATH" ":" prefix (,python-path)))
                #t))))))
     (inputs
      `(("python-mpd2" ,python-mpd2)
diff --git a/gnu/packages/music.scm b/gnu/packages/music.scm
index cf4e068fad..c9e2a81ec1 100644
--- a/gnu/packages/music.scm
+++ b/gnu/packages/music.scm
@@ -1711,9 +1711,9 @@ (define-public solfege
            (lambda* (#:key inputs outputs #:allow-other-keys)
              ;; Make sure 'solfege' runs with the correct PYTHONPATH.
              (let* ((out (assoc-ref outputs "out"))
-                    (path (getenv "PYTHONPATH")))
+                    (path (getenv "GUIX_PYTHONPATH")))
                (wrap-program (string-append out "/bin/solfege")
-                 `("PYTHONPATH" ":" prefix (,path))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,path))))
              #t)))))
     (inputs
      `(("python" ,python-2)
diff --git a/gnu/packages/networking.scm b/gnu/packages/networking.scm
index a00ce4c60e..9a51e6b9f5 100644
--- a/gnu/packages/networking.scm
+++ b/gnu/packages/networking.scm
@@ -621,7 +621,7 @@ (define-public blueman
                (for-each
                 (lambda (program)
                   (wrap-program program
-                    `("PYTHONPATH" = (,(getenv "PYTHONPATH") ,lib))
+                    `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH") ,lib))
                     `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH")))))
                 (append
                  (map (lambda (prog) (string-append bin prog))
diff --git a/gnu/packages/patchutils.scm b/gnu/packages/patchutils.scm
index 1354c860a5..444f458657 100644
--- a/gnu/packages/patchutils.scm
+++ b/gnu/packages/patchutils.scm
@@ -348,7 +348,7 @@ (define-public patchwork
                  ;; as the python modules in this package in the wsgi.py file,
                  ;; as this will ensure they are available at runtime.
                  (define pythonpath
-                   (string-append (getenv "PYTHONPATH")
+                   (string-append (getenv "GUIX_PYTHONPATH")
                                   ":"
                                   (site-packages inputs outputs)))
                  (display
diff --git a/gnu/packages/photo.scm b/gnu/packages/photo.scm
index 5402826fd6..fc4467c0cb 100644
--- a/gnu/packages/photo.scm
+++ b/gnu/packages/photo.scm
@@ -156,13 +156,13 @@ (define-public rapid-photo-downloader
                                               "/bin"))
                                        ":"))
                    (gi-typelib-path   (getenv "GI_TYPELIB_PATH"))
-                   (python-path       (getenv "PYTHONPATH")))
+                   (python-path       (getenv "GUIX_PYTHONPATH")))
                (for-each
                 (lambda (program)
                   (wrap-program program
                     `("PATH" ":" prefix (,path))
                     `("GI_TYPELIB_PATH" ":" prefix (,gi-typelib-path))
-                    `("PYTHONPATH"             ":" prefix (,python-path))))
+                    `("GUIX_PYTHONPATH"             ":" prefix (,python-path))))
                 (map (lambda (name)
                        (string-append out "/bin/" name))
                      '("analyze-pv-structure"
@@ -655,10 +655,10 @@ (define-public entangle
            (lambda* (#:key inputs outputs #:allow-other-keys)
              (let ((out               (assoc-ref outputs "out"))
                    (gi-typelib-path   (getenv "GI_TYPELIB_PATH"))
-                   (python-path       (getenv "PYTHONPATH")))
+                   (python-path       (getenv "GUIX_PYTHONPATH")))
                (wrap-program (string-append out "/bin/entangle")
                  `("GI_TYPELIB_PATH" ":" prefix (,gi-typelib-path))
-                 `("PYTHONPATH" ":" prefix (,python-path))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,python-path))))
              #t)))))
     (native-inputs
      `(("cmake" ,cmake)
diff --git a/gnu/packages/plotutils.scm b/gnu/packages/plotutils.scm
index 8928bbddd5..b34eb0d299 100644
--- a/gnu/packages/plotutils.scm
+++ b/gnu/packages/plotutils.scm
@@ -308,9 +308,9 @@ (define-public asymptote
            (lambda* (#:key inputs outputs #:allow-other-keys)
              ;; Make sure 'xasy' runs with the correct PYTHONPATH.
              (let* ((out (assoc-ref outputs "out"))
-                    (path (getenv "PYTHONPATH")))
+                    (path (getenv "GUIX_PYTHONPATH")))
                (wrap-program (string-append out "/share/asymptote/GUI/xasy.py")
-                 `("PYTHONPATH" ":" prefix (,path))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,path))))
              #t)))))
     (home-page "http://asymptote.sourceforge.net")
     (synopsis "Script-based vector graphics language")
diff --git a/gnu/packages/presentation.scm b/gnu/packages/presentation.scm
index 0ad407d36c..8d24a81f9d 100644
--- a/gnu/packages/presentation.scm
+++ b/gnu/packages/presentation.scm
@@ -62,12 +62,12 @@ (define-public presentty
                      `("PATH" ":" prefix (,(dirname (which "cowsay"))
                                           ,(dirname (which "figlet"))
                                           ,(dirname (which "jp2a"))))
-                     `("PYTHONPATH" prefix
+                     `("GUIX_PYTHONPATH" prefix
                        ,(cons (string-append out "/lib/python"
                                              (python-version python)
                                              "/site-packages")
                               (search-path-as-string->list
-                                (or (getenv "PYTHONPATH") ""))))))
+                                (or (getenv "GUIX_PYTHONPATH") ""))))))
                  '("presentty" "presentty-console")))
              #t)))))
     (inputs
diff --git a/gnu/packages/screen.scm b/gnu/packages/screen.scm
index 0491731e20..40584d7445 100644
--- a/gnu/packages/screen.scm
+++ b/gnu/packages/screen.scm
@@ -138,7 +138,7 @@ (define-public byobu
                    (select (string-append out "/bin/byobu-select-session")))
               (wrap-program config
                 `("BYOBU_PYTHON" = (,python))
-                `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH"))))
+                `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH"))))
               (wrap-program select
                 `("BYOBU_PYTHON" = (,python)))
               #t))))))
diff --git a/gnu/packages/storage.scm b/gnu/packages/storage.scm
index d53327df75..978ecd5b5e 100644
--- a/gnu/packages/storage.scm
+++ b/gnu/packages/storage.scm
@@ -170,7 +170,7 @@ (define-public ceph
                ;; the install directory is not on PYTHONPATH.
                (setenv "PYTHONPATH"
                        (string-append py3sitedir ":"
-                                      (getenv "PYTHONPATH")))
+                                      (getenv "GUIX_PYTHONPATH")))
                #t)))
          (add-after 'install 'wrap-python-scripts
            (lambda* (#:key inputs outputs #:allow-other-keys)
@@ -190,7 +190,7 @@ (define-public ceph
                                  (sitedir prettytable))))
                (for-each (lambda (executable)
                            (wrap-program (string-append out "/bin/" executable)
-                             `("PYTHONPATH" ":" prefix (,PYTHONPATH))))
+                             `("GUIX_PYTHONPATH" ":" prefix (,PYTHONPATH))))
                          scripts)
                #t))))))
     (outputs
diff --git a/gnu/packages/syndication.scm b/gnu/packages/syndication.scm
index efe231c92f..9b7d84b3ce 100644
--- a/gnu/packages/syndication.scm
+++ b/gnu/packages/syndication.scm
@@ -205,10 +205,10 @@ (define-public liferea
            (lambda* (#:key inputs outputs #:allow-other-keys)
              (let ((out               (assoc-ref outputs "out"))
                    (gi-typelib-path   (getenv "GI_TYPELIB_PATH"))
-                   (python-path       (getenv "PYTHONPATH")))
+                   (python-path       (getenv "GUIX_PYTHONPATH")))
                (wrap-program (string-append out "/bin/liferea")
                  `("GI_TYPELIB_PATH" ":" prefix (,gi-typelib-path))
-                 `("PYTHONPATH" ":" prefix (,python-path))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,python-path))))
              #t)))))
     (native-inputs
      `(("autoconf" ,autoconf)
diff --git a/gnu/packages/task-management.scm b/gnu/packages/task-management.scm
index 3c0efe13e2..47a355213d 100644
--- a/gnu/packages/task-management.scm
+++ b/gnu/packages/task-management.scm
@@ -96,11 +96,11 @@ (define-public blanket
              (let* ((out               (assoc-ref outputs "out"))
                     (gi-typelib-path   (getenv "GI_TYPELIB_PATH"))
                     (gst-plugin-path   (getenv "GST_PLUGIN_SYSTEM_PATH"))
-                    (python-path       (getenv "PYTHONPATH")))
+                    (python-path       (getenv "GUIX_PYTHONPATH")))
                (wrap-program (string-append out "/bin/blanket")
                  `("GI_TYPELIB_PATH" ":" prefix (,gi-typelib-path))
                  `("GST_PLUGIN_SYSTEM_PATH" ":" prefix (,gst-plugin-path))
-                 `("PYTHONPATH" ":" prefix (,python-path))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,python-path))))
              #t)))))
     (native-inputs
      `(("desktop-file-utils" ,desktop-file-utils)
diff --git a/gnu/packages/text-editors.scm b/gnu/packages/text-editors.scm
index 81915ca52b..ddc67225bb 100644
--- a/gnu/packages/text-editors.scm
+++ b/gnu/packages/text-editors.scm
@@ -650,7 +650,7 @@ (define-public manuskript
                (let ((bin (string-append out "/bin"))
                      (executable (string-append share "/bin/manuskript")))
                  (wrap-program executable
-                   (list "PYTHONPATH" 'prefix (list (getenv "PYTHONPATH"))))
+                   (list "PYTHONPATH" 'prefix (list (getenv "GUIX_PYTHONPATH"))))
                  (mkdir-p bin)
                  (with-directory-excursion bin
                    (symlink (string-append share "/bin/manuskript")
diff --git a/gnu/packages/version-control.scm b/gnu/packages/version-control.scm
index da0ab44f0d..45b68a41ad 100644
--- a/gnu/packages/version-control.scm
+++ b/gnu/packages/version-control.scm
@@ -619,12 +619,12 @@ (define-public gitless
                    (git (assoc-ref inputs "git")))
                (wrap-program (string-append out "/bin/gl")
                  `("PATH" ":" prefix (,(string-append git "/bin")))
-                 `("PYTHONPATH" ":" =
+                 `("GUIX_PYTHONPATH" ":" =
                    (,(string-append out "/lib/python"
                                     ,(version-major+minor
                                       (package-version python))
                                     "/site-packages:")
-                    ,(getenv "PYTHONPATH"))))
+                    ,(getenv "GUIX_PYTHONPATH"))))
                #t))))))
     (native-inputs
      `(("git-for-tests" ,git-minimal)))
@@ -925,7 +925,7 @@ (define (quoted-file-name input path)
               (lambda (file)
                 (wrap-program (string-append (assoc-ref outputs "out")
                                              "/lib/cgit/filters/" file)
-                  `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH")))))
+                  `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH")))))
               '("syntax-highlighting.py"
                 "html-converters/md2html"))
              #t)))))
@@ -2604,7 +2604,7 @@ (define-public git-when-merged
              (lambda* (#:key outputs #:allow-other-keys)
                (wrap-program (string-append (assoc-ref outputs "out")
                                             "/bin/git-when-merged")
-                 `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH"))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH"))))
                #t)))))
       (inputs
        `(("git" ,git)
@@ -2649,7 +2649,7 @@ (define-public git-imerge
            (lambda* (#:key outputs #:allow-other-keys)
              (wrap-program (string-append (assoc-ref outputs "out")
                                           "/bin/git-imerge")
-               `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH"))))
+               `("GUIX_PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH"))))
              #t)))))
     (inputs
      `(("git" ,git)
diff --git a/gnu/packages/video.scm b/gnu/packages/video.scm
index 824ea62273..313eaa0776 100644
--- a/gnu/packages/video.scm
+++ b/gnu/packages/video.scm
@@ -4052,7 +4052,7 @@ (define-public pitivi
               (let ((prog (string-append (assoc-ref outputs "out")
                                          "/bin/pitivi")))
                 (wrap-program prog
-                  `("PYTHONPATH" = (,(getenv "PYTHONPATH")))
+                  `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH")))
                   `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH")))
                   ;; We've only added inputs for what Pitivi deems either
                   ;; necessary or optional.  Let the user's packages take
diff --git a/gnu/packages/virtualization.scm b/gnu/packages/virtualization.scm
index 59c35afffc..4470bedee7 100644
--- a/gnu/packages/virtualization.scm
+++ b/gnu/packages/virtualization.scm
@@ -1335,9 +1335,9 @@ (define-public criu
                                          (string-take (string-take-right
                                                        (assoc-ref inputs "python") 5) 3)
                                          "/site-packages:"
-                                         (or (getenv "PYTHONPATH") ""))))
+                                         (or (getenv "GUIX_PYTHONPATH") ""))))
                (wrap-program (string-append out "/bin/crit")
-                 `("PYTHONPATH" ":" prefix (,path))))
+                 `("GUIX_PYTHONPATH" ":" prefix (,path))))
              #t)))))
     (inputs
      `(("protobuf" ,protobuf)
diff --git a/gnu/packages/xfce.scm b/gnu/packages/xfce.scm
index 2192f61dc7..544416a410 100644
--- a/gnu/packages/xfce.scm
+++ b/gnu/packages/xfce.scm
@@ -241,7 +241,7 @@ (define-public catfish
            (lambda* (#:key outputs #:allow-other-keys)
              (let ((out (assoc-ref outputs "out")))
                (wrap-program (string-append out "/bin/catfish")
-                 `("PYTHONPATH" = (,(getenv "PYTHONPATH")))
+                 `("GUIX_PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH")))
                  `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH"))))))))
        #:tests? #f))
     (native-inputs