diff --git a/gcc/testsuite/g++.dg/opt/alias1.C b/gcc/testsuite/g++.dg/opt/alias1.C
index 34aed593532..b5ed92c1492 100644
--- a/gcc/testsuite/g++.dg/opt/alias1.C
+++ b/gcc/testsuite/g++.dg/opt/alias1.C
@@ -1,6 +1,6 @@
 // Test that type punning using an anonymous union works with strict aliasing.
 // { dg-do run }
-// { dg-options -O2 -fstrict-aliasing }
+// { dg-options "-O2 -fstrict-aliasing" }
 
 extern "C" void abort ();