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 aaa1a16800..3a6a351dc1 100644
--- a/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm
+++ b/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm
@@ -78,8 +78,8 @@ using namespace juce;
 
 struct AudioProcessorHolder  : public ReferenceCountedObject
 {
-    AudioProcessorHolder() {}
-    AudioProcessorHolder (AudioProcessor* p) : processor (p) {}
+    AudioProcessorHolder() = default;
+    explicit AudioProcessorHolder (AudioProcessor* p) : processor (p) {}
     AudioProcessor& operator*() noexcept        { return *processor; }
     AudioProcessor* operator->() noexcept       { return processor.get(); }
     AudioProcessor* get() noexcept              { return processor.get(); }
@@ -225,7 +225,7 @@ public:
     }
 
     //==============================================================================
-    AUAudioUnitPreset* getCurrentPreset()
+    AUAudioUnitPreset* getCurrentPreset() const
     {
         return factoryPresets.getAtIndex (getAudioProcessor().getCurrentProgram());
     }
@@ -235,12 +235,12 @@ public:
         getAudioProcessor().setCurrentProgram (static_cast<int> ([preset number]));
     }
 
-    NSArray<AUAudioUnitPreset*>* getFactoryPresets()
+    NSArray<AUAudioUnitPreset*>* getFactoryPresets() const
     {
         return factoryPresets.get();
     }
 
-    NSDictionary<NSString*, id>* getFullState()
+    NSDictionary<NSString*, id>* getFullState() const
     {
         NSMutableDictionary<NSString*, id>* retval = [[NSMutableDictionary<NSString*, id> alloc] init];
 
@@ -316,12 +316,12 @@ public:
         [modifiedState release];
     }
 
-    AUParameterTree* getParameterTree()
+    AUParameterTree* getParameterTree() const
     {
         return paramTree.get();
     }
 
-    NSArray<NSNumber*>* parametersForOverviewWithCount (int count)
+    NSArray<NSNumber*>* parametersForOverviewWithCount (int count) const
     {
         const int n = static_cast<int> ([overviewParams.get() count]);
 
@@ -335,21 +335,21 @@ public:
     }
 
     //==============================================================================
-    NSTimeInterval getLatency()
+    NSTimeInterval getLatency() const
     {
         auto& p = getAudioProcessor();
         return p.getLatencySamples() / p.getSampleRate();
     }
 
-    NSTimeInterval getTailTime()
+    NSTimeInterval getTailTime() const
     {
         return getAudioProcessor().getTailLengthSeconds();
     }
 
     //==============================================================================
-    AUAudioUnitBusArray* getInputBusses()             { return inputBusses.get();  }
-    AUAudioUnitBusArray* getOutputBusses()            { return outputBusses.get(); }
-    NSArray<NSNumber*>* getChannelCapabilities()      { return channelCapabilities.get(); }
+    AUAudioUnitBusArray* getInputBusses()             const { return inputBusses.get();  }
+    AUAudioUnitBusArray* getOutputBusses()            const { return outputBusses.get(); }
+    NSArray<NSNumber*>* getChannelCapabilities()      const { return channelCapabilities.get(); }
 
     bool shouldChangeToFormat (AVAudioFormat* format, AUAudioUnitBus* auBus)
     {
@@ -396,7 +396,7 @@ public:
     }
 
     //==============================================================================
-    int getVirtualMIDICableCount()
+    int getVirtualMIDICableCount() const
     {
        #if JucePlugin_WantsMidiInput
         return 1;
@@ -405,12 +405,12 @@ public:
        #endif
     }
 
-    bool getSupportsMPE()
+    bool getSupportsMPE() const
     {
         return getAudioProcessor().supportsMPE();
     }
 
-    NSArray<NSString*>* getMIDIOutputNames()
+    NSArray<NSString*>* getMIDIOutputNames() const
     {
        #if JucePlugin_ProducesMidiOutput
         return @[@"MIDI Out"];
@@ -420,8 +420,8 @@ public:
     }
 
     //==============================================================================
-    AUInternalRenderBlock getInternalRenderBlock()    { return internalRenderBlock; }
-    bool getRenderingOffline()                        { return getAudioProcessor().isNonRealtime(); }
+    AUInternalRenderBlock getInternalRenderBlock() const  { return internalRenderBlock; }
+    bool getRenderingOffline()                     const  { return getAudioProcessor().isNonRealtime(); }
     void setRenderingOffline (bool offline)
     {
         auto& processor = getAudioProcessor();
@@ -436,7 +436,7 @@ public:
         }
     }
 
-    bool getShouldBypassEffect()
+    bool getShouldBypassEffect() const
     {
         if (bypassParam != nullptr)
             return (bypassParam->getValue() != 0.0f);
@@ -1084,7 +1084,7 @@ private:
     }
 
     // When parameters are discrete we need to use integer values.
-    float getMaximumParameterValue (AudioProcessorParameter* juceParam)
+    float getMaximumParameterValue (AudioProcessorParameter* juceParam) const
     {
        #if JUCE_FORCE_LEGACY_PARAMETER_AUTOMATION_TYPE
         ignoreUnused (juceParam);
@@ -1536,7 +1536,7 @@ private:
         }
     }
 
-    AUValue getValue (AUParameter* param)
+    AUValue getValue (AUParameter* param) const
     {
         if (param != nullptr)
         {
diff --git a/modules/juce_core/native/juce_mac_ObjCHelpers.h b/modules/juce_core/native/juce_mac_ObjCHelpers.h
index 8995472d65..ac67c4d75a 100644
--- a/modules/juce_core/native/juce_mac_ObjCHelpers.h
+++ b/modules/juce_core/native/juce_mac_ObjCHelpers.h
@@ -492,13 +492,31 @@ Class* getJuceClassFromNSObject (NSObject* obj)
     return obj != nullptr ? getIvar<Class*> (obj, "cppObject") : nullptr;
 }
 
-template <typename ReturnT, class Class, typename... Params>
-ReturnT (^CreateObjCBlock(Class* object, ReturnT (Class::*fn)(Params...))) (Params...)
+namespace detail
 {
-    __block Class* _this = object;
-    __block ReturnT (Class::*_fn)(Params...) = fn;
+template <typename> struct Signature;
+template <typename R, typename... A> struct Signature<R (A...)> {};
 
-    return [[^ReturnT (Params... params) { return (_this->*_fn) (params...); } copy] autorelease];
+template <typename Class, typename Result, typename... Args>
+constexpr auto getSignature (Result (Class::*) (Args...))       { return Signature<Result (Args...)>{}; }
+
+template <typename Class, typename Result, typename... Args>
+constexpr auto getSignature (Result (Class::*) (Args...) const) { return Signature<Result (Args...)>{}; }
+
+template <typename Class, typename Fn, typename Result, typename... Params>
+auto createObjCBlockImpl (Class* object, Fn func, Signature<Result (Params...)>)
+{
+    __block auto _this = object;
+    __block auto _func = func;
+
+    return [[^Result (Params... params) { return (_this->*_func) (params...); } copy] autorelease];
+}
+} // namespace detail
+
+template <typename Class, typename MemberFunc>
+auto CreateObjCBlock (Class* object, MemberFunc fn)
+{
+    return detail::createObjCBlockImpl (object, fn, detail::getSignature (fn));
 }
 
 template <typename BlockType>