diff --git a/reactos/dll/win32/winmm/winmm.c b/reactos/dll/win32/winmm/winmm.c
index 10033f29adc..325f0d5f5b3 100644
--- a/reactos/dll/win32/winmm/winmm.c
+++ b/reactos/dll/win32/winmm/winmm.c
@@ -2551,7 +2551,7 @@ UINT WINAPI waveInGetDevCapsA(UINT_PTR uDeviceID, LPWAVEINCAPSA lpCaps, UINT uSi
 /**************************************************************************
  * 				waveInOpen			[WINMM.@]
  */
-MMRESULT WINAPI waveInOpen(HWAVEIN* lphWaveIn, UINT uDeviceID,
+MMRESULT WINAPI waveInOpen(LPHWAVEIN lphWaveIn, UINT uDeviceID,
 		       LPCWAVEFORMATEX lpFormat, DWORD_PTR dwCallback,
 		       DWORD_PTR dwInstance, DWORD dwFlags)
 {
diff --git a/reactos/drivers/wdm/audio/legacy/wdmaud/control.c b/reactos/drivers/wdm/audio/legacy/wdmaud/control.c
index d30423e4f2f..d4b0cfef07b 100644
--- a/reactos/drivers/wdm/audio/legacy/wdmaud/control.c
+++ b/reactos/drivers/wdm/audio/legacy/wdmaud/control.c
@@ -352,7 +352,7 @@ CheckFormatSupport(
 
         if (DataRangeAudio->MaximumBitsPerSample <= 16 && DataRangeAudio->MaximumBitsPerSample >= 16)
         {
-            Result |= Monot16;
+            Result |= Mono16Bit;
             if (DataRangeAudio->MaximumChannels >= 2)
             {
                 Result |= Stereo8Bit;
diff --git a/reactos/include/psdk/mmsystem.h b/reactos/include/psdk/mmsystem.h
index 359e94e1594..c7bd9cede11 100644
--- a/reactos/include/psdk/mmsystem.h
+++ b/reactos/include/psdk/mmsystem.h
@@ -1660,7 +1660,7 @@ MMRESULT WINAPI waveOutGetVolume(HWAVEOUT,PDWORD);
 MMRESULT WINAPI waveOutSetVolume(HWAVEOUT,DWORD);
 MMRESULT WINAPI waveOutGetErrorTextA(MMRESULT,LPSTR,UINT);
 MMRESULT WINAPI waveOutGetErrorTextW(MMRESULT,LPWSTR,UINT);
-MMRESULT WINAPI waveOutOpen(LPHWAVEOUT,UINT,LPWAVEFORMATEX,DWORD_PTR,DWORD_PTR,DWORD);
+MMRESULT WINAPI waveOutOpen(LPHWAVEOUT,UINT,LPCWAVEFORMATEX,DWORD_PTR,DWORD_PTR,DWORD);
 MMRESULT WINAPI waveOutClose(HWAVEOUT);
 MMRESULT WINAPI waveOutPrepareHeader(HWAVEOUT,LPWAVEHDR,UINT);
 MMRESULT WINAPI waveOutUnprepareHeader(HWAVEOUT,LPWAVEHDR,UINT);
@@ -1687,7 +1687,7 @@ MMRESULT WINAPI waveInGetDevCapsA(UINT_PTR,LPWAVEINCAPSA,UINT);
 MMRESULT WINAPI waveInGetDevCapsW(UINT_PTR,LPWAVEINCAPSW,UINT);
 MMRESULT WINAPI waveInGetErrorTextA(MMRESULT,LPSTR,UINT);
 MMRESULT WINAPI waveInGetErrorTextW(MMRESULT,LPWSTR,UINT);
-MMRESULT WINAPI waveInOpen(LPHWAVEIN,UINT,LPWAVEFORMATEX,DWORD_PTR,DWORD_PTR,DWORD);
+MMRESULT WINAPI waveInOpen(LPHWAVEIN,UINT,LPCWAVEFORMATEX,DWORD_PTR,DWORD_PTR,DWORD);
 MMRESULT WINAPI waveInClose(HWAVEIN);
 MMRESULT WINAPI waveInPrepareHeader(HWAVEIN,LPWAVEHDR,UINT);
 MMRESULT WINAPI waveInUnprepareHeader(HWAVEIN,LPWAVEHDR,UINT);