diff --git a/modules/juce_audio_devices/native/juce_ios_Audio.cpp b/modules/juce_audio_devices/native/juce_ios_Audio.cpp
index f0da9809a1..599f56f805 100644
--- a/modules/juce_audio_devices/native/juce_ios_Audio.cpp
+++ b/modules/juce_audio_devices/native/juce_ios_Audio.cpp
@@ -682,7 +682,8 @@ private:
         UInt32 framesPerSlice;
         UInt32 dataSize = sizeof (framesPerSlice);
 
-        if (AudioUnitGetProperty (audioUnit, kAudioUnitProperty_MaximumFramesPerSlice, kAudioUnitScope_Global, 0, &framesPerSlice, &dataSize) == noErr
+        if (AudioUnitSetProperty (audioUnit, kAudioUnitProperty_MaximumFramesPerSlice, kAudioUnitScope_Global, 0, &actualBufferSize, sizeof (actualBufferSize)) == noErr
+               && AudioUnitGetProperty (audioUnit, kAudioUnitProperty_MaximumFramesPerSlice, kAudioUnitScope_Global, 0, &framesPerSlice, &dataSize) == noErr
                && dataSize == sizeof (framesPerSlice) && framesPerSlice != actualBufferSize)
         {
             actualBufferSize = framesPerSlice;