diff --git a/lang/cem/ctest/ctgen/run1 b/lang/cem/ctest/ctgen/run1
index 55277e7f1..cc5cbae6c 100755
--- a/lang/cem/ctest/ctgen/run1
+++ b/lang/cem/ctest/ctgen/run1
@@ -1,3 +1,9 @@
+case $2 in
+clean)
+	;;
+*)
 make "TS=$1"
+;;
+esac
 make "P=$1" -fk ../makefile $2
 rm -f $1.[ckmos]