diff --git a/modules/juce_audio_processors/utilities/juce_AudioProcessorValueTreeState.h b/modules/juce_audio_processors/utilities/juce_AudioProcessorValueTreeState.h
index 1ef3e4ad2b..18ebd40412 100644
--- a/modules/juce_audio_processors/utilities/juce_AudioProcessorValueTreeState.h
+++ b/modules/juce_audio_processors/utilities/juce_AudioProcessorValueTreeState.h
@@ -543,7 +543,12 @@ private:
 
     const Identifier valueType { "PARAM" }, valuePropertyID { "value" }, idPropertyID { "id" };
 
-    std::map<String, std::unique_ptr<ParameterAdapter>> adapterTable;
+    struct StringRefLessThan final
+    {
+        bool operator() (StringRef a, StringRef b) const noexcept { return a.text.compare (b.text) < 0; }
+    };
+
+    std::map<StringRef, std::unique_ptr<ParameterAdapter>, StringRefLessThan> adapterTable;
 
     CriticalSection valueTreeChanging;