diff --git a/dll/win32/beepmidi/beepmidi.c b/dll/win32/beepmidi/beepmidi.c
index b23999845f9..5ab0287dd4d 100644
--- a/dll/win32/beepmidi/beepmidi.c
+++ b/dll/win32/beepmidi/beepmidi.c
@@ -83,7 +83,7 @@ typedef struct _DeviceInfo
     HDRVR mme_handle;
     HANDLE kernel_device;
 
-    DWORD callback;
+    DWORD_PTR callback;
     DWORD instance;
     DWORD flags;