diff --git a/dlls/winecoreaudio.drv/midi.c b/dlls/winecoreaudio.drv/midi.c
index 98d7d8f..27c87cb 100644
--- a/dlls/winecoreaudio.drv/midi.c
+++ b/dlls/winecoreaudio.drv/midi.c
@@ -711,8 +711,8 @@
     if (dwSize < sizeof(MIDIHDR) || lpMidiHdr == 0 ||
 	lpMidiHdr->lpData == 0 || (lpMidiHdr->dwFlags & MHDR_INQUEUE) != 0 ||
 	lpMidiHdr->dwBufferLength >= 0x10000ul) {
-	WARN("Invalid parameter %p %p %08x %d/%d\n", lpMidiHdr, lpMidiHdr->lpData,
-	           lpMidiHdr->dwFlags, sizeof(MIDIHDR), dwSize);
+	WARN("Invalid parameter %p %p %08x %d\n", lpMidiHdr, lpMidiHdr->lpData,
+	           lpMidiHdr->dwFlags, dwSize);
 	return MMSYSERR_INVALPARAM;
     }