diff --git a/gnu/packages/radio.scm b/gnu/packages/radio.scm
index f7d348a242..9f92b30b39 100644
--- a/gnu/packages/radio.scm
+++ b/gnu/packages/radio.scm
@@ -400,7 +400,7 @@ (define-public gnuradio
             (variable "GRC_BLOCKS_PATH")
             (files '("share/gnuradio/grc/blocks")))
            (search-path-specification
-            (variable "PYTHONPATH")
+            (variable "GUIX_PYTHONPATH")
             (files (list (string-append "lib/python"
                                         (version-major+minor
                                          (package-version python))