diff --git a/Source/Core/AudioCommon/Src/Mixer.h b/Source/Core/AudioCommon/Src/Mixer.h
index 144d22a183..991a2f9149 100644
--- a/Source/Core/AudioCommon/Src/Mixer.h
+++ b/Source/Core/AudioCommon/Src/Mixer.h
@@ -45,12 +45,12 @@ public:
 
 	// Called from main thread
 	virtual void PushSamples(const short* samples, unsigned int num_samples);
-	unsigned int GetSampleRate() {return m_sampleRate;}
+	unsigned int GetSampleRate() const {return m_sampleRate;}
 
 	void SetThrottle(bool use) { m_throttle = use;}
 
 	// TODO: do we need this
-	bool IsHLEReady() { return m_HLEready;}
+	bool IsHLEReady() const { return m_HLEready;}
 	void SetHLEReady(bool ready) { m_HLEready = ready;}
 	// ---------------------
 
diff --git a/Source/Core/AudioCommon/Src/SoundStream.h b/Source/Core/AudioCommon/Src/SoundStream.h
index b7b0b20a58..ac2ac6bbb2 100644
--- a/Source/Core/AudioCommon/Src/SoundStream.h
+++ b/Source/Core/AudioCommon/Src/SoundStream.h
@@ -33,7 +33,7 @@ public:
 	virtual void Stop() {}
 	virtual void Update() {}
 	virtual void Clear(bool mute) { m_muted = mute; }
-	bool IsMuted() { return m_muted; }
+	bool IsMuted() const { return m_muted; }
 	virtual void StartLogAudio(const char *filename) {
 		if (! m_logAudio) {
 			m_logAudio = true;
diff --git a/Source/Core/AudioCommon/Src/WaveFile.h b/Source/Core/AudioCommon/Src/WaveFile.h
index 26f528aace..c0ccd8136b 100644
--- a/Source/Core/AudioCommon/Src/WaveFile.h
+++ b/Source/Core/AudioCommon/Src/WaveFile.h
@@ -39,7 +39,7 @@ public:
 
 	void AddStereoSamples(const short *sample_data, u32 count);
 	void AddStereoSamplesBE(const short *sample_data, u32 count);  // big endian
-	u32 GetAudioSize() { return audio_size; }
+	u32 GetAudioSize() const { return audio_size; }
 };
 
 #endif  // _WAVEFILE_H_
diff --git a/Source/Core/Core/Src/FifoPlayer/FifoPlayer.h b/Source/Core/Core/Src/FifoPlayer/FifoPlayer.h
index b99093f164..982cd0643f 100644
--- a/Source/Core/Core/Src/FifoPlayer/FifoPlayer.h
+++ b/Source/Core/Core/Src/FifoPlayer/FifoPlayer.h
@@ -29,22 +29,22 @@ public:
 	FifoDataFile *GetFile() { return m_File; }
 
 	u32 GetFrameObjectCount();
-	u32 GetCurrentFrameNum() { return m_CurrentFrame; }
+	u32 GetCurrentFrameNum() const { return m_CurrentFrame; }
 
-	const AnalyzedFrameInfo& GetAnalyzedFrameInfo(u32 frame) { return m_FrameInfo[frame]; }
+	const AnalyzedFrameInfo& GetAnalyzedFrameInfo(u32 frame) const { return m_FrameInfo[frame]; }
 
 	// Frame range
-	u32 GetFrameRangeStart() { return m_FrameRangeStart; }
+	u32 GetFrameRangeStart() const { return m_FrameRangeStart; }
 	void SetFrameRangeStart(u32 start);
 
-	u32 GetFrameRangeEnd() { return m_FrameRangeEnd; }
+	u32 GetFrameRangeEnd() const { return m_FrameRangeEnd; }
 	void SetFrameRangeEnd(u32 end);
 
 	// Object range
-	u32 GetObjectRangeStart() { return m_ObjectRangeStart; }
+	u32 GetObjectRangeStart() const { return m_ObjectRangeStart; }
 	void SetObjectRangeStart(u32 start) { m_ObjectRangeStart = start; }
 
-	u32 GetObjectRangeEnd() { return m_ObjectRangeEnd; }
+	u32 GetObjectRangeEnd() const { return m_ObjectRangeEnd; }
 	void SetObjectRangeEnd(u32 end)  { m_ObjectRangeEnd = end; }
 
 	// If enabled then all memory updates happen at once before the first frame