diff --git a/pkgs/tools/text/groff/default.nix b/pkgs/tools/text/groff/default.nix
index 039bff8c655..e08c10fd9ed 100644
--- a/pkgs/tools/text/groff/default.nix
+++ b/pkgs/tools/text/groff/default.nix
@@ -35,9 +35,9 @@ stdenv.mkDerivation rec {
   postInstall = ''
       # Remove example output with (random?) colors to 
       # avoid non-determinism in the output
-      rm $out/share/doc/${name}/examples/hdtbl/*color*ps
+      rm $doc/share/doc/examples/hdtbl/*color*ps
       # Remove creation date
-      find $out/share/doc/${name} -type f -print0 | xargs -0 sed -i -e 's/%%CreationDate: .*//'
+      find $doc/share/doc/ -type f -print0 | xargs -0 sed -i -e 's/%%CreationDate: .*//'
     '';
 
   meta = with stdenv.lib; {