diff --git a/src/os_vms_conf.h b/src/os_vms_conf.h
index ade1ea3..4058e4a 100644
--- a/src/os_vms_conf.h
+++ b/src/os_vms_conf.h
@@ -23,7 +23,7 @@
 #define HAVE_DATE_TIME
 
 /* Defined to the size of an int */
-#define SIZEOF_INT 4
+#define VIM_SIZEOF_INT 4
 
 /* #undef USEBCOPY */
 #define USEMEMMOVE