diff --git a/include/vmsconf.h b/include/vmsconf.h
index ea6ef1af5..6a28c11b7 100644
--- a/include/vmsconf.h
+++ b/include/vmsconf.h
@@ -29,9 +29,11 @@
 /* #define VMS9 */
 
 #ifdef VMS9
+#ifndef __cplusplus
 /* for version.c */
 typedef int64_t ssize_t;
 #endif
+#endif
 
 /*
  * This section cleans up the stuff done in config.h so that it