diff --git a/guix/build/ruby-build-system.scm b/guix/build/ruby-build-system.scm
index ba0de1259e..49400b204d 100644
--- a/guix/build/ruby-build-system.scm
+++ b/guix/build/ruby-build-system.scm
@@ -143,14 +143,13 @@ (define* (install #:key inputs outputs (gem-flags '())
          (gem-dir (string-append vendor-dir "/gems/" gem-name)))
     (setenv "GEM_VENDOR" vendor-dir)
 
-    (or (zero?
-         (apply system* "gem" "install" gem-file
-                "--verbose"
-                "--local" "--ignore-dependencies" "--vendor"
-                ;; Executables should go into /bin, not
-                ;; /lib/ruby/gems.
-                "--bindir" (string-append out "/bin")
-                gem-flags))
+    (or (apply invoke "gem" "install" gem-file
+               "--verbose"
+               "--local" "--ignore-dependencies" "--vendor"
+               ;; Executables should go into /bin, not
+               ;; /lib/ruby/gems.
+               "--bindir" (string-append out "/bin")
+               gem-flags)
         (begin
           (let ((failed-output-dir (string-append (getcwd) "/out")))
             (mkdir failed-output-dir)