diff --git a/win32/except.c b/win32/except.c
index c30bca4f3e1..8289788e4d3 100644
--- a/win32/except.c
+++ b/win32/except.c
@@ -304,7 +304,8 @@ static BOOL	start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
     else
     {
         cmdline = HeapAlloc(GetProcessHeap(), 0, 80);
-        sprintf(cmdline, "winedbg --debugmsg -all --auto %ld %p", GetCurrentProcessId(), hEvent);
+        sprintf(cmdline, "winedbg --debugmsg -all --auto %ld %ld",
+                GetCurrentProcessId(), (ULONG_PTR)hEvent);
     }
 
     if (!bAuto)