diff --git a/gcc/testsuite/gcc.dg/cpp-ifparen.c b/gcc/testsuite/gcc.dg/cpp-ifparen.c
index 39e112eb664d7141eb7bd36b208b58c7dac64e4f..b1c8ed30430d6da3cc01b8269571d971e01e01ed 100644
--- a/gcc/testsuite/gcc.dg/cpp-ifparen.c
+++ b/gcc/testsuite/gcc.dg/cpp-ifparen.c
@@ -1,3 +1,5 @@
+/* { dg-do preprocess } */
+
 #if 2048 < (16 * (40) + 192)
 #error			/* { dg-bogus "error" "with paren" } */
 #endif