diff --git a/modules/audio_processing/aec3/suppression_gain.cc b/modules/audio_processing/aec3/suppression_gain.cc
index ea7af50..c1f12b7 100644
--- a/modules/audio_processing/aec3/suppression_gain.cc
+++ b/modules/audio_processing/aec3/suppression_gain.cc
@@ -390,8 +390,8 @@
     const std::vector<std::vector<std::vector<float>>>& render) {
   float x2_sum = 0.f;
   float x2_max = 0.f;
-  for (auto x_ch : render[0]) {
-    for (auto x_k : x_ch) {
+  for (const auto& x_ch : render[0]) {
+    for (const auto& x_k : x_ch) {
       const float x2 = x_k * x_k;
       x2_sum += x2;
       x2_max = std::max(x2_max, x2);