diff --git a/extras/audio plugins/wrapper/formats/AudioUnit/juce_AudioUnitWrapper.cpp b/extras/audio plugins/wrapper/formats/AudioUnit/juce_AudioUnitWrapper.cpp
index 8ed299888b..5c61ffa900 100644
--- a/extras/audio plugins/wrapper/formats/AudioUnit/juce_AudioUnitWrapper.cpp	
+++ b/extras/audio plugins/wrapper/formats/AudioUnit/juce_AudioUnitWrapper.cpp	
@@ -604,6 +604,8 @@ public:
                         memcpy (channels [numInChans], (const float*) buf.mData, sizeof (float) * numSamples);
                     else
                         channels [numInChans] = (float*) buf.mData;
+
+                    ++numInChans;
                 }
                 else
                 {