2 files changed, 14 insertions, 12 deletions
diff --git a/engines/m4/m4.cpp b/engines/m4/m4.cpp
index 67201c2aff..45185b3b86 100644
--- a/engines/m4/m4.cpp
+++ b/engines/m4/m4.cpp
@@ -141,7 +141,7 @@ M4Engine::~M4Engine() {
 	delete _resourceManager;
 }
 
-int M4Engine::init() {
+Common::Error M4Engine::init() {
 	// Initialize backend
 	_system->beginGFXTransaction();
 	initCommonGFX(isM4());
@@ -197,7 +197,7 @@ int M4Engine::init() {
 	_random = new Common::RandomSource();
 	g_system->getEventManager()->registerRandomSource(*_random, "m4");
 
-	return 0;
+	return Common::kNoError;
 }
 
 void M4Engine::eventHandler() {
@@ -272,14 +272,14 @@ void M4Engine::loadMenu(MenuType menuType, bool loadSaveFromHotkey, bool calledF
 	_viewManager->moveToFront(view);
 }
 
-int M4Engine::go() {
+Common::Error M4Engine::go() {
 	if (isM4())
 		return goM4();
 	else
 		return goMADS();
 }
 
-int M4Engine::goMADS() {
+Common::Error M4Engine::goMADS() {
 	_palette->setMadsSystemPalette();
 
 	_mouse->init("cursor.ss", NULL);
@@ -351,10 +351,10 @@ int M4Engine::goMADS() {
 		g_system->delayMillis(10);
 	}
 
-	return 0;
+	return Common::kNoError;
 }
 
-int M4Engine::goM4() {
+Common::Error M4Engine::goM4() {
 
 	_script->open("m4.dat");
 
@@ -375,7 +375,7 @@ int M4Engine::goM4() {
 	}
 #endif
 
-	return 0;
+	return Common::kNoError;
 #endif
 
 	// Set up the inventory
@@ -520,7 +520,7 @@ int M4Engine::goM4() {
 		g_system->delayMillis(10);
 	}
 
-	return 0;
+	return Common::kNoError;
 }
 
 void M4Engine::dumpFile(const char* filename, bool uncompress) {
diff --git a/engines/m4/m4.h b/engines/m4/m4.h
index e989bcc4e6..ac3262e7b8 100644
--- a/engines/m4/m4.h
+++ b/engines/m4/m4.h
@@ -107,12 +107,14 @@ FORCEINLINE long FixedDiv(long a, long b) { return (long)(((float)a / (float)b)
 
 class M4Engine : public Engine {
 private:
-	int goMADS();
-	int goM4();
+	Common::Error goMADS();
+	Common::Error goM4();
 
 protected:
-	int init();
-	int go();
+	// Engine APIs
+	virtual Common::Error init();
+	virtual Common::Error go();
+
 	void shutdown();
 	
 	MidiPlayer *_midi;