diff --git a/clisp.spec b/clisp.spec
index 11c7cab..fb33afb 100644
--- a/clisp.spec
+++ b/clisp.spec
@@ -207,6 +207,7 @@ unset noexec nommap safety
 %ifarch s390x
 $CC $MYCFLAGS -o test-s390x %{S:42}
 ./test-s390x
+CC="gcc -g3 -O -fno-strict-aliasing -fPIC -pipe"
 %endif
 
 #