diff --git a/dlls/winmm/playsound.c b/dlls/winmm/playsound.c
index e1badecfe62..54db68f0f8e 100644
--- a/dlls/winmm/playsound.c
+++ b/dlls/winmm/playsound.c
@@ -376,7 +376,7 @@ static DWORD WINAPI proc_PlaySound(LPVOID arg)
 	  (LPSTR)&mmckInfo.ckid, mmckInfo.fccType, mmckInfo.cksize);
 
     lpWaveFormat = HeapAlloc(GetProcessHeap(), 0, mmckInfo.cksize);
-    if (mmioRead(hmmio, (HPSTR)lpWaveFormat, mmckInfo.cksize) < sizeof(WAVEFORMAT))
+    if (mmioRead(hmmio, (HPSTR)lpWaveFormat, mmckInfo.cksize) < sizeof(PCMWAVEFORMAT))
 	goto errCleanUp;
 
     TRACE("wFormatTag=%04X !\n", 	lpWaveFormat->wFormatTag);