diff --git a/gnu/packages/gcc.scm b/gnu/packages/gcc.scm
index 4e01a7af61..18aaa0bdab 100644
--- a/gnu/packages/gcc.scm
+++ b/gnu/packages/gcc.scm
@@ -320,8 +320,7 @@ (define-public gcc-4.7
                   ;; but there's nothing useful to look for here.)
                   (substitute* "gcc/config.in"
                     (("PREFIX_INCLUDE_DIR")
-                     "PREFIX_INCLUDE_DIR_isnt_necessary_here"))
-                  #t)))
+                     "PREFIX_INCLUDE_DIR_isnt_necessary_here")))))
 
             (add-after 'configure 'post-configure
               (lambda _
@@ -329,8 +328,7 @@ (define-public gcc-4.7
                 ;; build-time dependencies---e.g., `--with-ppl=/gnu/store/xxx'.
                 (substitute* "Makefile"
                   (("^TOPLEVEL_CONFIGURE_ARGUMENTS=(.*)$" _ rest)
-                   "TOPLEVEL_CONFIGURE_ARGUMENTS=\n"))
-                #t)))))
+                   "TOPLEVEL_CONFIGURE_ARGUMENTS=\n")))))))
 
        (native-search-paths
         ;; Use the language-specific variables rather than 'CPATH' because they
@@ -446,8 +444,7 @@ (define-public gcc-4.9
                                           ":"))
                      (format #t
                              "environment variable `CPLUS_INCLUDE_PATH' changed to ~a~%"
-                             (getenv "CPLUS_INCLUDE_PATH"))
-                     #t))))))))))
+                             (getenv "CPLUS_INCLUDE_PATH"))))))))))))
 
 (define-public gcc-5
   ;; Note: GCC >= 5 ships with .info files but 'make install' fails to install
@@ -647,16 +644,14 @@ (define (make-libiberty gcc)
        (modify-phases %standard-phases
          (add-before 'configure 'chdir
            (lambda _
-             (chdir "libiberty")
-             #t))
+             (chdir "libiberty")))
          (replace 'install
            (lambda* (#:key outputs #:allow-other-keys)
              (let* ((out     (assoc-ref outputs "out"))
                     (lib     (string-append out "/lib/"))
                     (include (string-append out "/include/")))
                (install-file "libiberty.a" lib)
-               (install-file "../include/libiberty.h" include))
-             #t)))))
+               (install-file "../include/libiberty.h" include)))))))
     (inputs '())
     (outputs '("out"))
     (native-inputs '())
@@ -698,8 +693,7 @@ (define* (custom-gcc gcc name languages
              (lambda* (#:key outputs #:allow-other-keys)
                (for-each delete-file
                          (find-files (string-append (assoc-ref outputs "out") "/bin")
-                                     ".*(c\\+\\+|cpp|g\\+\\+|gcov|gcc|gcc-.*)"))
-               #t))))))))
+                                     ".*(c\\+\\+|cpp|g\\+\\+|gcov|gcc|gcc-.*)"))))))))))
 
 (define %generic-search-paths
   ;; This is the language-neutral search path for GCC.  Entries in $CPATH are
@@ -753,8 +747,7 @@ (define-public libgccjit
              (lambda* (#:key outputs #:allow-other-keys)
                (for-each delete-file
                          (find-files (string-append (assoc-ref outputs "out") "/bin")
-                                     ".*(c\\+\\+|cpp|g\\+\\+|gcov|gcc|gcc-.*)"))
-               #t))))))
+                                     ".*(c\\+\\+|cpp|g\\+\\+|gcov|gcc|gcc-.*)"))))))))
     (synopsis "GCC library generating machine code on-the-fly at runtime")
     (description
      "This package is part of the GNU Compiler Collection and provides an
@@ -887,8 +880,7 @@ (define (make-libstdc++-doc gcc)
        #:phases (modify-phases %standard-phases
                   (add-before 'configure 'chdir
                               (lambda _
-                                (chdir "libstdc++-v3")
-                                #t))
+                                (chdir "libstdc++-v3")))
                   (add-before 'configure 'set-xsl-directory
                               (lambda* (#:key inputs #:allow-other-keys)
                                 (let ((docbook (assoc-ref inputs "docbook-xsl")))
@@ -897,8 +889,7 @@ (define (make-libstdc++-doc gcc)
                                     (("@XSL_STYLE_DIR@")
                                      (string-append
                                       docbook "/xml/xsl/"
-                                      (strip-store-file-name docbook))))
-                                  #t)))
+                                      (strip-store-file-name docbook)))))))
                   (replace 'build
                            (lambda _
                              ;; XXX: There's also a 'doc-info' target, but it
@@ -955,8 +946,7 @@ (define-public isl
                         ;; libtool looks for it in the usual locations.
                         (substitute* (string-append out "/lib/libisl.la")
                           (("^old_library=.*")
-                           "old_library=''\n"))
-                        #t))))))
+                           "old_library=''\n"))))))))
     (inputs `(("gmp" ,gmp)))
     (home-page "http://isl.gforge.inria.fr/")
     (synopsis
@@ -1082,8 +1072,7 @@ (define-public gnu-c-manual
                                            (copy-file file
                                                       (string-append html "/"
                                                                      file)))
-                                         (find-files "." "\\.html$"))
-                               #t))))))
+                                         (find-files "." "\\.html$"))))))))
     (synopsis "Reference manual for the C programming language")
     (description
      "This is a reference manual for the C programming language, as