diff --git a/src/modules/audio_conference_mixer/source/audio_conference_mixer_impl.cc b/src/modules/audio_conference_mixer/source/audio_conference_mixer_impl.cc
index ba4c82954e..e7ec069c3b 100644
--- a/src/modules/audio_conference_mixer/source/audio_conference_mixer_impl.cc
+++ b/src/modules/audio_conference_mixer/source/audio_conference_mixer_impl.cc
@@ -625,9 +625,30 @@ WebRtc_Word32 AudioConferenceMixerImpl::SetMinimumMixingFrequency(
 // Check all AudioFrames that are to be mixed. The highest sampling frequency
 // found is the lowest that can be used without losing information.
 WebRtc_Word32 AudioConferenceMixerImpl::GetLowestMixingFrequency()
+{
+    const int participantListFrequency =
+        GetLowestMixingFrequencyFromList(_participantList);
+    const int anonymousListFrequency =
+        GetLowestMixingFrequencyFromList(_additionalParticipantList);
+    const int highestFreq =
+        (participantListFrequency > anonymousListFrequency) ?
+            participantListFrequency : anonymousListFrequency;
+    // Check if the user specified a lowest mixing frequency.
+    if(_minimumMixingFreq != kLowestPossible)
+    {
+        if(_minimumMixingFreq > highestFreq)
+        {
+            return _minimumMixingFreq;
+        }
+    }
+    return highestFreq;
+}
+
+WebRtc_Word32 AudioConferenceMixerImpl::GetLowestMixingFrequencyFromList(
+    ListWrapper& mixList)
 {
     WebRtc_Word32 highestFreq = 8000;
-    ListItem* item = _participantList.First();
+    ListItem* item = mixList.First();
     while(item)
     {
         MixerParticipant* participant =
@@ -637,16 +658,7 @@ WebRtc_Word32 AudioConferenceMixerImpl::GetLowestMixingFrequency()
         {
             highestFreq = neededFrequency;
         }
-        item = _participantList.Next(item);
-    }
-
-    // Check if the user specified a lowest mixing frequency.
-    if(_minimumMixingFreq != kLowestPossible)
-    {
-        if(_minimumMixingFreq > highestFreq)
-        {
-            return _minimumMixingFreq;
-        }
+        item = mixList.Next(item);
     }
     return highestFreq;
 }
diff --git a/src/modules/audio_conference_mixer/source/audio_conference_mixer_impl.h b/src/modules/audio_conference_mixer/source/audio_conference_mixer_impl.h
index 6c961b93e3..f20e8ab20b 100644
--- a/src/modules/audio_conference_mixer/source/audio_conference_mixer_impl.h
+++ b/src/modules/audio_conference_mixer/source/audio_conference_mixer_impl.h
@@ -104,6 +104,7 @@ private:
     // Return the lowest mixing frequency that can be used without having to
     // downsample any audio.
     WebRtc_Word32 GetLowestMixingFrequency();
+    WebRtc_Word32 GetLowestMixingFrequencyFromList(ListWrapper& mixList);
 
     // Return the AudioFrames that should be mixed anonymously.
     void GetAdditionalAudio(ListWrapper& additionalFramesList);