diff --git a/modules/audio_mixer/audio_frame_manipulator.cc b/modules/audio_mixer/audio_frame_manipulator.cc
index 92526a7d09..e8a5f759b0 100644
--- a/modules/audio_mixer/audio_frame_manipulator.cc
+++ b/modules/audio_mixer/audio_frame_manipulator.cc
@@ -21,7 +21,8 @@ uint32_t AudioMixerCalculateEnergy(const AudioFrame& audio_frame) {
 
   uint32_t energy = 0;
   const int16_t* frame_data = audio_frame.data();
-  for (size_t position = 0; position < audio_frame.samples_per_channel_;
+  for (size_t position = 0;
+       position < audio_frame.samples_per_channel_ * audio_frame.num_channels_;
        position++) {
     // TODO(aleloi): This can overflow. Convert to floats.
     energy += frame_data[position] * frame_data[position];