diff --git a/test/FrontendC/2011-03-18-StructReturn.c b/test/FrontendC/2011-03-18-StructReturn.c
index 9c47709283d..f6b8c3dafd0 100644
--- a/test/FrontendC/2011-03-18-StructReturn.c
+++ b/test/FrontendC/2011-03-18-StructReturn.c
@@ -1,4 +1,4 @@
-// RUN: %llvmgcc %s -S -O0 -o - | FileCheck %s
+// RUN: %llvmgcc %s -m64 -S -O0 -o - | FileCheck %s
 // XTARGET: x86_64-apple-darwin
 // Radar 9156771
 typedef struct RGBColor {