diff --git a/dlls/ole2nls.dll16/ole2nls.c b/dlls/ole2nls.dll16/ole2nls.c
index b21601b5390..68db4498ae5 100644
--- a/dlls/ole2nls.dll16/ole2nls.c
+++ b/dlls/ole2nls.dll16/ole2nls.c
@@ -104,10 +104,9 @@ INT16 WINAPI LCMapString16(LCID lcid, DWORD mapflags, LPCSTR srcstr, INT16 srcle
 /***********************************************************************
  *           CompareStringA       (OLE2NLS.8)
  */
-UINT16 WINAPI CompareString16(DWORD lcid,DWORD fdwStyle,
-                              LPCSTR s1,DWORD l1,LPCSTR s2,DWORD l2)
+INT16 WINAPI CompareString16(LCID lcid, DWORD flags, LPCSTR str1, INT16 len1, LPCSTR str2, INT16 len2)
 {
-	return (UINT16)CompareStringA(lcid,fdwStyle,s1,l1,s2,l2);
+    return CompareStringA(lcid, flags, str1, len1, str2, len2);
 }
 
 /******************************************************************************
diff --git a/include/wine/winbase16.h b/include/wine/winbase16.h
index 310d5f6c5ee..f2f32a2ce02 100644
--- a/include/wine/winbase16.h
+++ b/include/wine/winbase16.h
@@ -435,7 +435,7 @@ VOID        WINAPI _LeaveWin16Lock(void);
 
 INT16       WINAPI AccessResource16(HINSTANCE16,HRSRC16);
 ATOM        WINAPI AddAtom16(LPCSTR);
-UINT16      WINAPI CompareString16(DWORD,DWORD,LPCSTR,DWORD,LPCSTR,DWORD);
+INT16       WINAPI CompareString16(LCID,DWORD,LPCSTR,INT16,LPCSTR,INT16);
 BOOL16      WINAPI CreateDirectory16(LPCSTR,LPVOID);
 BOOL16      WINAPI DefineHandleTable16(WORD);
 ATOM        WINAPI DeleteAtom16(ATOM);