diff --git a/contrib/ocs b/contrib/ocs
index e924f4f..bd556b4 100755
--- a/contrib/ocs
+++ b/contrib/ocs
@@ -210,7 +210,7 @@ exp_inc()
     then
 	for i in `cat ${theInc}`
 	do
-	    printf "-I $i "
+	    printf -- "-I $i "
 	done
     fi
 }
-- 
2.26.2