diff --git a/skeletons/GeneralizedTime.c b/skeletons/GeneralizedTime.c
index 5a3120d..9e8375e 100644
--- a/skeletons/GeneralizedTime.c
+++ b/skeletons/GeneralizedTime.c
@@ -9,6 +9,13 @@
 #include <assert.h>
 #endif	/* __NO_ASSERT_H__ */
 
+#ifdef	WIN32
+#define	localtime_r(tlocp, tmp)	(*tmp = localtime(&tlocp))
+#warning PLEASE STOP AND READ!
+#warning localtime_r is implemented via localtime(), which is not thread-safe. You must fix the code to insert appropriate locking if you want to use asn_GT2time() or asn_UT2time().
+#warning PLEASE STOP AND READ!
+#endif
+
 #ifndef	__NO_ASN_TABLE__
 
 /*