diff --git a/modules/juce_audio_processors/processors/juce_AudioProcessor.cpp b/modules/juce_audio_processors/processors/juce_AudioProcessor.cpp
index 078c9387fb..675a3cfeeb 100644
--- a/modules/juce_audio_processors/processors/juce_AudioProcessor.cpp
+++ b/modules/juce_audio_processors/processors/juce_AudioProcessor.cpp
@@ -541,10 +541,13 @@ void AudioProcessor::addParameterGroup (std::unique_ptr<AudioProcessorParameterG
 
 void AudioProcessor::setParameterTree (AudioProcessorParameterGroup&& newTree)
 {
-   #if JUCE_DEBUG
+  #if JUCE_DEBUG
     paramIDs.clear();
     groupIDs.clear();
+   #if ! JUCE_DISABLE_CAUTIOUS_PARAMETER_ID_CHECKING
+    trimmedParamIDs.clear();
    #endif
+  #endif
 
     parameterTree = std::move (newTree);
     checkForDuplicateGroupIDs (parameterTree);