diff --git a/src/voice_engine/main/source/output_mixer.cc b/src/voice_engine/main/source/output_mixer.cc
index 11108c9382..c5ba0bfac8 100644
--- a/src/voice_engine/main/source/output_mixer.cc
+++ b/src/voice_engine/main/source/output_mixer.cc
@@ -586,7 +586,10 @@ OutputMixer::GetMixedAudio(const WebRtc_Word32 desiredFreqHz,
     {
         AudioFrameOperations::MonoToStereo(audioFrame);
     }
-
+    else if ((channels == 1) && (audioFrame.num_channels_ == 2))
+    {
+        AudioFrameOperations::StereoToMono(audioFrame);
+    }
     return 0;
 }