diff --git a/pjlib/include/pj/compat/cc_msvc.h b/pjlib/include/pj/compat/cc_msvc.h
index 57f97a3..291ecc8 100644
--- a/pjlib/include/pj/compat/cc_msvc.h
+++ b/pjlib/include/pj/compat/cc_msvc.h
@@ -57,4 +57,7 @@
 typedef __int64 pj_int64_t;
 typedef unsigned __int64 pj_uint64_t;
 
+#define PJ_INT64_FMT	"I64"
+
+
 #endif	/* __PJ_COMPAT_CC_MSVC_H__ */