diff --git a/guix/build-system/cmake.scm b/guix/build-system/cmake.scm
index 9461b19a2e350a3f2dd6490d1e98fe7842c652f2..38f11cb3c33a4e55ef2df91333310759572e6a96 100644
--- a/guix/build-system/cmake.scm
+++ b/guix/build-system/cmake.scm
@@ -65,7 +65,6 @@ (define* (cmake-build store name source inputs
                                          (guix build gnu-build-system)
                                          (guix build utils)))
                      (modules '((guix build cmake-build-system)
-                                (guix build gnu-build-system)
                                 (guix build utils))))
   "Build SOURCE using CMAKE, and with INPUTS. This assumes that SOURCE
 provides a 'CMakeLists.txt' file as its build system."
diff --git a/guix/build-system/perl.scm b/guix/build-system/perl.scm
index eac8f53d3ee76f2b38b2969565664bf946c9e00e..5dc50d97f3879658344101a35c31f788dfb5f5e1 100644
--- a/guix/build-system/perl.scm
+++ b/guix/build-system/perl.scm
@@ -57,7 +57,6 @@ (define* (perl-build store name source inputs
                                          (guix build gnu-build-system)
                                          (guix build utils)))
                      (modules '((guix build perl-build-system)
-                                (guix build gnu-build-system)
                                 (guix build utils))))
   "Build SOURCE using PERL, and with INPUTS.  This assumes that SOURCE
 provides a `Makefile.PL' file as its build system."