diff --git a/modules/juce_audio_processors/format_types/juce_AudioUnitPluginFormat.mm b/modules/juce_audio_processors/format_types/juce_AudioUnitPluginFormat.mm
index 3cb70160c5..db45291f18 100644
--- a/modules/juce_audio_processors/format_types/juce_AudioUnitPluginFormat.mm
+++ b/modules/juce_audio_processors/format_types/juce_AudioUnitPluginFormat.mm
@@ -1275,7 +1275,7 @@ private:
     };
 
     OwnedArray<ParamInfo> parameters;
-    HashMap<AudioUnitParameterID, size_t> paramIDToIndex;
+    HashMap<uint32, size_t> paramIDToIndex;
 
     MidiDataConcatenator midiConcatenator;
     CriticalSection midiInLock;