diff --git a/include/mmsystem.h b/include/mmsystem.h
index 1e163012e0..83b94c528e 100644
--- a/include/mmsystem.h
+++ b/include/mmsystem.h
@@ -631,7 +631,6 @@ UINT16		WINAPI	midiOutGetErrorText16(UINT16,LPSTR,UINT16);
 UINT		WINAPI	midiOutGetErrorTextA(UINT,LPSTR,UINT);
 UINT		WINAPI	midiOutGetErrorTextW(UINT,LPWSTR,UINT);
 #define 		midiOutGetErrorText WINELIB_NAME_AW(midiOutGetErrorText)
-UINT16		WINAPI	midiGetErrorText(UINT16,LPSTR,UINT16);
 UINT16		WINAPI	midiOutOpen16(HMIDIOUT16*,UINT16,DWORD,DWORD,DWORD);
 UINT		WINAPI	midiOutOpen(HMIDIOUT*,UINT,DWORD,DWORD,DWORD);
 UINT16		WINAPI	midiOutClose16(HMIDIOUT16);