diff --git a/crypto/impl_dispatch_test.cc b/crypto/impl_dispatch_test.cc
index 8297e22..10a4d1b 100644
--- a/crypto/impl_dispatch_test.cc
+++ b/crypto/impl_dispatch_test.cc
@@ -57,7 +57,7 @@
 
     f();
 
-    for (const auto flag : flags) {
+    for (const auto& flag : flags) {
       SCOPED_TRACE(flag.first);
 
       ASSERT_LT(flag.first, sizeof(BORINGSSL_function_hit));