diff --git a/source/Mockingboard.cpp b/source/Mockingboard.cpp
index 37588f5d..8d2e8738 100644
--- a/source/Mockingboard.cpp
+++ b/source/Mockingboard.cpp
@@ -1447,6 +1447,11 @@ void MB_InitializeForLoadingSnapshot()	// GH#609
 {
 	MB_Reset();
 	InitSoundcardType();
+
+	if (g_bDisableDirectSound || g_bDisableDirectSoundMockingboard)
+		return;
+
+	_ASSERT(MockingboardVoice.lpDSBvoice);
 	MockingboardVoice.lpDSBvoice->Stop();	// Reason: 'MB voice is playing' then loading a save-state where 'no MB present'
 }
 
@@ -1701,6 +1706,9 @@ void MB_InitializeIO(LPBYTE pCxRomPeripheral, UINT uSlot4, UINT uSlot5)
 
 	MB_SetSoundcardType(g_Slot[4]);
 
+	if (g_bDisableDirectSound || g_bDisableDirectSoundMockingboard)
+		return;
+
 	// Sound buffer may have been stopped by MB_InitializeForLoadingSnapshot().
 	// NB. DSZeroVoiceBuffer() also zeros the sound buffer, so it's better than directly calling IDirectSoundBuffer::Play():
 	// - without zeroing, then the previous sound buffer can be heard for a fraction of a second
diff --git a/source/SoundCore.cpp b/source/SoundCore.cpp
index c1ae5303..6ec6c623 100644
--- a/source/SoundCore.cpp
+++ b/source/SoundCore.cpp
@@ -235,6 +235,7 @@ bool DSZeroVoiceBuffer(PVOICE Voice, char* pszDevName, DWORD dwBufferSize)
 	DWORD dwDSLockedBufferSize = 0;    // Size of the locked DirectSound buffer
 	SHORT* pDSLockedBuffer;
 
+	_ASSERT(Voice->lpDSBvoice);
 	HRESULT hr = Voice->lpDSBvoice->Stop();
 	if(FAILED(hr))
 	{