diff --git a/engine/src/flutter/display_list/effects/dl_color_source.h b/engine/src/flutter/display_list/effects/dl_color_source.h
index 094006eb3ef..39359d7996a 100644
--- a/engine/src/flutter/display_list/effects/dl_color_source.h
+++ b/engine/src/flutter/display_list/effects/dl_color_source.h
@@ -644,7 +644,7 @@ class DlRuntimeEffectColorSource final : public DlColorSource {
         uniform_data_(std::move(uniform_data)) {}
 
   bool isUIThreadSafe() const override {
-    for (auto sampler : samplers_) {
+    for (const auto& sampler : samplers_) {
       if (!sampler->isUIThreadSafe()) {
         return false;
       }