diff --git a/audio/adlib.cpp b/audio/adlib.cpp
index 09bc8cb3df1..081aa168a7e 100644
--- a/audio/adlib.cpp
+++ b/audio/adlib.cpp
@@ -933,21 +933,21 @@ class MidiDriver_ADLIB : public MidiDriver {
 public:
 	MidiDriver_ADLIB();
 
-	int open();
-	void close();
+	int open() override;
+	void close() override;
 	void send(uint32 b) override;
 	void send(byte channel, uint32 b); // Supports higher than channel 15
-	uint32 property(int prop, uint32 param);
-	bool isOpen() const { return _isOpen; }
-	uint32 getBaseTempo() { return 1000000 / OPL::OPL::kDefaultCallbackFrequency; }
+	uint32 property(int prop, uint32 param) override;
+	bool isOpen() const override { return _isOpen; }
+	uint32 getBaseTempo() override { return 1000000 / OPL::OPL::kDefaultCallbackFrequency; }
 
-	void setPitchBendRange(byte channel, uint range);
-	void sysEx_customInstrument(byte channel, uint32 type, const byte *instr);
+	void setPitchBendRange(byte channel, uint range) override;
+	void sysEx_customInstrument(byte channel, uint32 type, const byte *instr) override;
 
-	MidiChannel *allocateChannel();
-	MidiChannel *getPercussionChannel() { return &_percussion; } // Percussion partially supported
+	MidiChannel *allocateChannel() override;
+	MidiChannel *getPercussionChannel() override { return &_percussion; } // Percussion partially supported
 
-	virtual void setTimerCallback(void *timerParam, Common::TimerManager::TimerProc timerProc);
+	virtual void setTimerCallback(void *timerParam, Common::TimerManager::TimerProc timerProc) override;
 
 private:
 	bool _scummSmallHeader; // FIXME: This flag controls a special mode for SCUMM V3 games
diff --git a/audio/midiplayer.h b/audio/midiplayer.h
index f2ffb558c75..7b81cd97051 100644
--- a/audio/midiplayer.h
+++ b/audio/midiplayer.h
@@ -116,7 +116,7 @@ public:
 
 	// MidiDriver_BASE implementation
 	virtual void send(uint32 b) override;
-	virtual void metaEvent(byte type, byte *data, uint16 length);
+	virtual void metaEvent(byte type, byte *data, uint16 length) override;
 
 protected:
 	/**
diff --git a/audio/miles_adlib.cpp b/audio/miles_adlib.cpp
index 3c39af6b2b9..1450b102229 100644
--- a/audio/miles_adlib.cpp
+++ b/audio/miles_adlib.cpp
@@ -121,19 +121,19 @@ public:
 	virtual ~MidiDriver_Miles_AdLib();
 
 	// MidiDriver
-	int open();
-	void close();
+	int open() override;
+	void close() override;
 	void send(uint32 b) override;
-	MidiChannel *allocateChannel() { return NULL; }
-	MidiChannel *getPercussionChannel() { return NULL; }
+	MidiChannel *allocateChannel() override { return NULL; }
+	MidiChannel *getPercussionChannel() override { return NULL; }
 
-	bool isOpen() const { return _isOpen; }
-	uint32 getBaseTempo() { return 1000000 / OPL::OPL::kDefaultCallbackFrequency; }
+	bool isOpen() const override { return _isOpen; }
+	uint32 getBaseTempo() override { return 1000000 / OPL::OPL::kDefaultCallbackFrequency; }
 
 	void setVolume(byte volume);
-	virtual uint32 property(int prop, uint32 param);
+	virtual uint32 property(int prop, uint32 param) override;
 
-	void setTimerCallback(void *timerParam, Common::TimerManager::TimerProc timerProc);
+	void setTimerCallback(void *timerParam, Common::TimerManager::TimerProc timerProc) override;
 
 private:
 	bool _modeOPL3;
diff --git a/audio/miles_mt32.cpp b/audio/miles_mt32.cpp
index 66c9754773f..dc42e84112d 100644
--- a/audio/miles_mt32.cpp
+++ b/audio/miles_mt32.cpp
@@ -75,29 +75,29 @@ public:
 	virtual ~MidiDriver_Miles_MT32();
 
 	// MidiDriver
-	int open();
-	void close();
-	bool isOpen() const { return _isOpen; }
+	int open() override;
+	void close() override;
+	bool isOpen() const override { return _isOpen; }
 
 	void send(uint32 b) override;
 
-	MidiChannel *allocateChannel() {
+	MidiChannel *allocateChannel() override {
 		if (_driver)
 			return _driver->allocateChannel();
 		return NULL;
 	}
-	MidiChannel *getPercussionChannel() {
+	MidiChannel *getPercussionChannel() override {
 		if (_driver)
 			return _driver->getPercussionChannel();
 		return NULL;
 	}
 
-	void setTimerCallback(void *timer_param, Common::TimerManager::TimerProc timer_proc) {
+	void setTimerCallback(void *timer_param, Common::TimerManager::TimerProc timer_proc) override {
 		if (_driver)
 			_driver->setTimerCallback(timer_param, timer_proc);
 	}
 
-	uint32 getBaseTempo() {
+	uint32 getBaseTempo() override {
 		if (_driver) {
 			return _driver->getBaseTempo();
 		}
diff --git a/audio/softsynth/fluidsynth.cpp b/audio/softsynth/fluidsynth.cpp
index ed1d442120b..c66243348d5 100644
--- a/audio/softsynth/fluidsynth.cpp
+++ b/audio/softsynth/fluidsynth.cpp
@@ -57,21 +57,21 @@ protected:
 	void setNum(const char *name, double num);
 	void setStr(const char *name, const char *str);
 
-	void generateSamples(int16 *buf, int len);
+	void generateSamples(int16 *buf, int len) override;
 
 public:
 	MidiDriver_FluidSynth(Audio::Mixer *mixer);
 
-	int open();
-	void close();
+	int open() override;
+	void close() override;
 	void send(uint32 b) override;
 
-	MidiChannel *allocateChannel();
-	MidiChannel *getPercussionChannel();
+	MidiChannel *allocateChannel() override;
+	MidiChannel *getPercussionChannel() override;
 
 	// AudioStream API
-	bool isStereo() const { return true; }
-	int getRate() const { return _outputRate; }
+	bool isStereo() const override { return true; }
+	int getRate() const override { return _outputRate; }
 };
 
 // MidiDriver method implementations
diff --git a/audio/softsynth/mt32.cpp b/audio/softsynth/mt32.cpp
index 2bbcb9ad069..a1590307a1b 100644
--- a/audio/softsynth/mt32.cpp
+++ b/audio/softsynth/mt32.cpp
@@ -114,25 +114,25 @@ private:
 	int _outputRate;
 
 protected:
-	void generateSamples(int16 *buf, int len);
+	void generateSamples(int16 *buf, int len) override;
 
 public:
 	MidiDriver_MT32(Audio::Mixer *mixer);
 	virtual ~MidiDriver_MT32();
 
-	int open();
-	void close();
+	int open() override;
+	void close() override;
 	void send(uint32 b) override;
-	void setPitchBendRange(byte channel, uint range);
-	void sysEx(const byte *msg, uint16 length);
+	void setPitchBendRange(byte channel, uint range) override;
+	void sysEx(const byte *msg, uint16 length) override;
 
-	uint32 property(int prop, uint32 param);
-	MidiChannel *allocateChannel();
-	MidiChannel *getPercussionChannel();
+	uint32 property(int prop, uint32 param) override;
+	MidiChannel *allocateChannel() override;
+	MidiChannel *getPercussionChannel() override;
 
 	// AudioStream API
-	bool isStereo() const { return true; }
-	int getRate() const { return _outputRate; }
+	bool isStereo() const override { return true; }
+	int getRate() const override { return _outputRate; }
 };
 
 ////////////////////////////////////////
diff --git a/backends/midi/coreaudio.cpp b/backends/midi/coreaudio.cpp
index 40acc252b8e..7e6c374361a 100644
--- a/backends/midi/coreaudio.cpp
+++ b/backends/midi/coreaudio.cpp
@@ -96,11 +96,11 @@ class MidiDriver_CORE : public MidiDriver_MPU401 {
 public:
 	MidiDriver_CORE();
 	~MidiDriver_CORE();
-	int open();
-	bool isOpen() const { return _auGraph != 0; }
-	void close();
+	int open() override;
+	bool isOpen() const override { return _auGraph != 0; }
+	void close() override;
 	void send(uint32 b) override;
-	void sysEx(const byte *msg, uint16 length);
+	void sysEx(const byte *msg, uint16 length) override;
 
 private:
 	void loadSoundFont(const char *soundfont);
diff --git a/backends/midi/coremidi.cpp b/backends/midi/coremidi.cpp
index 39c08fad613..0bc9c153ca8 100644
--- a/backends/midi/coremidi.cpp
+++ b/backends/midi/coremidi.cpp
@@ -55,11 +55,11 @@ class MidiDriver_CoreMIDI : public MidiDriver_MPU401 {
 public:
 	MidiDriver_CoreMIDI(ItemCount device);
 	~MidiDriver_CoreMIDI();
-	int open();
-	bool isOpen() const { return mOutPort != 0 && mDest != 0; }
-	void close();
+	int open() override;
+	bool isOpen() const override { return mOutPort != 0 && mDest != 0; }
+	void close() override;
 	void send(uint32 b) override;
-	void sysEx(const byte *msg, uint16 length);
+	void sysEx(const byte *msg, uint16 length) override;
 
 private:
 	ItemCount mDevice;
diff --git a/backends/midi/seq.cpp b/backends/midi/seq.cpp
index be768758dab..96b5b137e7d 100644
--- a/backends/midi/seq.cpp
+++ b/backends/midi/seq.cpp
@@ -54,11 +54,11 @@
 class MidiDriver_SEQ : public MidiDriver_MPU401 {
 public:
 	MidiDriver_SEQ();
-	int open();
-	bool isOpen() const { return _isOpen; }
-	void close();
+	int open() override;
+	bool isOpen() const override { return _isOpen; }
+	void close() override;
 	void send(uint32 b) override;
-	void sysEx(const byte *msg, uint16 length);
+	void sysEx(const byte *msg, uint16 length) override;
 
 private:
 	bool _isOpen;
diff --git a/backends/midi/timidity.cpp b/backends/midi/timidity.cpp
index 61887170b55..e8713f3fd4b 100644
--- a/backends/midi/timidity.cpp
+++ b/backends/midi/timidity.cpp
@@ -84,11 +84,11 @@ class MidiDriver_TIMIDITY : public MidiDriver_MPU401 {
 public:
 	MidiDriver_TIMIDITY();
 
-	int open();
-	bool isOpen() const { return _isOpen; }
-	void close();
+	int open() override;
+	bool isOpen() const override { return _isOpen; }
+	void close() override;
 	void send(uint32 b) override;
-	void sysEx(const byte *msg, uint16 length);
+	void sysEx(const byte *msg, uint16 length) override;
 
 private:
 	/* creates a tcp connection to TiMidity server, returns filedesc (like open()) */