diff --git a/pkgs/development/interpreters/acl2/default.nix b/pkgs/development/interpreters/acl2/default.nix
index 2d104e9fb4c4..9436cf58e427 100644
--- a/pkgs/development/interpreters/acl2/default.nix
+++ b/pkgs/development/interpreters/acl2/default.nix
@@ -98,7 +98,7 @@ in stdenv.mkDerivation rec {
 
     # Clean up some stuff to save space
     find -name '*@useless-runes.lsp' -execdir rm {} +  # saves ~1GB of space
-    find -name '*.cert.out' -execdir gz {} +           # saves ~400MB of space
+    find -name '*.cert.out' -execdir gzip {} +         # saves ~400MB of space
 
     popd
   '';