diff --git a/modules/juce_audio_plugin_client/AAX/juce_AAX_Wrapper.cpp b/modules/juce_audio_plugin_client/AAX/juce_AAX_Wrapper.cpp
index b4ae647e3e..a661c191be 100644
--- a/modules/juce_audio_plugin_client/AAX/juce_AAX_Wrapper.cpp
+++ b/modules/juce_audio_plugin_client/AAX/juce_AAX_Wrapper.cpp
@@ -1607,6 +1607,9 @@ namespace AAXClasses
                 audioProcessor.prepareToPlay (sampleRate, lastBufferSize);
                 maxBufferSize = lastBufferSize;
 
+                midiBuffer.ensureSize (2048);
+                midiBuffer.clear();
+
                 sideChainBuffer.calloc (static_cast<size_t> (maxBufferSize));
             }
 
diff --git a/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm b/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm
index 4950554957..8d138540d7 100644
--- a/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm
+++ b/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm
@@ -847,6 +847,9 @@ public:
         processor.setRateAndBufferSizeDetails (sampleRate, static_cast<int> (maxFrames));
         processor.prepareToPlay (sampleRate, static_cast<int> (maxFrames));
 
+        midiMessages.ensureSize (2048);
+        midiMessages.clear();
+
         zeromem (&lastAudioHead, sizeof (lastAudioHead));
         hostMusicalContextCallback = [getAudioUnit() musicalContextBlock];
         hostTransportStateCallback = [getAudioUnit() transportStateBlock];
diff --git a/modules/juce_audio_plugin_client/VST3/juce_VST3_Wrapper.cpp b/modules/juce_audio_plugin_client/VST3/juce_VST3_Wrapper.cpp
index 5f8f1058d4..80dc9a4fa0 100644
--- a/modules/juce_audio_plugin_client/VST3/juce_VST3_Wrapper.cpp
+++ b/modules/juce_audio_plugin_client/VST3/juce_VST3_Wrapper.cpp
@@ -2410,6 +2410,9 @@ private:
 
         p.setRateAndBufferSizeDetails (sampleRate, bufferSize);
         p.prepareToPlay (sampleRate, bufferSize);
+
+        midiBuffer.ensureSize (2048);
+        midiBuffer.clear();
     }
 
     //==============================================================================