diff --git a/modules/juce_audio_devices/audio_io/juce_AudioDeviceManager.cpp b/modules/juce_audio_devices/audio_io/juce_AudioDeviceManager.cpp
index a896536a08..732c058d10 100644
--- a/modules/juce_audio_devices/audio_io/juce_AudioDeviceManager.cpp
+++ b/modules/juce_audio_devices/audio_io/juce_AudioDeviceManager.cpp
@@ -427,6 +427,9 @@ String AudioDeviceManager::setAudioDeviceSetup (const AudioDeviceSetup& newSetup
 
     stopDevice();
 
+    if (! newSetup.useDefaultInputChannels)    numInputChansNeeded  = newSetup.inputChannels.countNumberOfSetBits();
+    if (! newSetup.useDefaultOutputChannels)   numOutputChansNeeded = newSetup.outputChannels.countNumberOfSetBits();
+
     auto newInputDeviceName  (numInputChansNeeded  == 0 ? String() : newSetup.inputDeviceName);
     auto newOutputDeviceName (numOutputChansNeeded == 0 ? String() : newSetup.outputDeviceName);