diff --git a/src/audio/AudioManager.h b/src/audio/AudioManager.h
index 9cbf8fab..04144b7e 100644
--- a/src/audio/AudioManager.h
+++ b/src/audio/AudioManager.h
@@ -393,7 +393,7 @@ public:
 	float GetDistanceSquared(const CVector &v) const; // inlined in vc
 	int32 GetJumboTaxiFreq() const; // inlined in vc
 	uint8 GetMissionAudioLoadingStatus(uint8 slot) const;
-	int8 GetMissionScriptPoliceAudioPlayingStatus() const;
+	int8 GetMissionScriptPoliceAudioPlayingStatus();
 	uint8 GetNum3DProvidersAvailable();
 	uint32 GetPedCommentSfx(CPed *ped, int32 sound);
 	void GetPhrase(uint32 &phrase, uint32 &prevPhrase, uint32 sample, uint32 maxOffset) const;
@@ -513,7 +513,7 @@ public:
 	void SetEntityStatus(int32 id, bool8 status);
 	uint32 SetLoopingCollisionRequestedSfxFreqAndGetVol(const cAudioCollision &audioCollision);
 	void SetMissionAudioLocation(uint8 slot, float x, float y, float z);
-	void SetMissionScriptPoliceAudio(int32 sfx) const; // inlined and optimized
+	void SetMissionScriptPoliceAudio(uint32 sfx); // inlined and optimized
 	void SetMonoMode(bool8 mono);
 	void SetMusicFadeVol(uint8 volume);
 	void SetMusicMasterVolume(uint8 volume);
diff --git a/src/audio/PolRadio.cpp b/src/audio/PolRadio.cpp
index fb2b06b4..d30b4826 100644
--- a/src/audio/PolRadio.cpp
+++ b/src/audio/PolRadio.cpp
@@ -23,7 +23,7 @@ struct tPoliceRadioZone {
 
 tPoliceRadioZone ZoneSfx[NUMAUDIOZONES];
 
-int32 g_nMissionAudioSfx = TOTAL_AUDIO_SAMPLES;
+uint32 g_nMissionAudioSfx = TOTAL_AUDIO_SAMPLES;
 int8 g_nMissionAudioPlayingStatus = 2;
 uint8 gSpecialSuspectLastSeenReport;
 uint32 gMinTimeToNextReport[NUM_CRIME_TYPES];
@@ -80,7 +80,7 @@ cAudioManager::ResetPoliceRadio()
 }
 
 void
-cAudioManager::SetMissionScriptPoliceAudio(int32 sfx) const
+cAudioManager::SetMissionScriptPoliceAudio(uint32 sfx)
 {
 	if (!m_bIsInitialised) return;
 	if (g_nMissionAudioPlayingStatus != 1) {
@@ -90,7 +90,7 @@ cAudioManager::SetMissionScriptPoliceAudio(int32 sfx) const
 }
 
 int8
-cAudioManager::GetMissionScriptPoliceAudioPlayingStatus() const
+cAudioManager::GetMissionScriptPoliceAudioPlayingStatus()
 {
 	return g_nMissionAudioPlayingStatus;
 }