2 files changed, 17 insertions, 3 deletions
diff --git a/audio/softsynth/fmtowns_pc98/towns_audio.cpp b/audio/softsynth/fmtowns_pc98/towns_audio.cpp
index 42824d8423..2506e02c2b 100644
--- a/audio/softsynth/fmtowns_pc98/towns_audio.cpp
+++ b/audio/softsynth/fmtowns_pc98/towns_audio.cpp
@@ -1940,14 +1940,14 @@ bool TownsAudioInterface::init() {
 	return _intf->init();
 }
 
-int TownsAudioInterface::callback(int command, ...) {
+TownsAudioInterface::ErrorCode TownsAudioInterface::callback(int command, ...) {
 	va_list args;
 	va_start(args, command);
 
 	int res = _intf->processCommand(command, args);
 
 	va_end(args);
-	return res;
+	return (TownsAudioInterface::ErrorCode)res;
 }
 
 void TownsAudioInterface::setMusicVolume(int volume) {
diff --git a/audio/softsynth/fmtowns_pc98/towns_audio.h b/audio/softsynth/fmtowns_pc98/towns_audio.h
index 0003f02777..ba13bd10f6 100644
--- a/audio/softsynth/fmtowns_pc98/towns_audio.h
+++ b/audio/softsynth/fmtowns_pc98/towns_audio.h
@@ -40,9 +40,23 @@ public:
 	TownsAudioInterface(Audio::Mixer *mixer, TownsAudioInterfacePluginDriver *driver, bool externalMutexHandling = false);
 	~TownsAudioInterface();
 
+	enum ErrorCode {
+		kSuccess = 0,
+		kInvalidChannel,
+		kUnavailable,
+		kArgumentOutOfRange,
+		kNotImplemented,
+		kOutOfWaveMemory,
+		kInvalidWaveTable,
+		kChannelNotReserved,
+		kNoteOutOfRangeForInstrument,
+		kNoMatchingWaveTable,
+		kDuplicateWaveTable
+	};
+
 	bool init();
 
-	int callback(int command, ...);
+	ErrorCode callback(int command, ...);
 
 	void setMusicVolume(int volume);
 	void setSoundEffectVolume(int volume);