diff --git a/src/structs.h b/src/structs.h
index d6d4a0f..c036bf1 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -5101,7 +5101,7 @@
 #define KEYVALUE_ENTRY(k, v) \
     {(k), {((char_u *)v), STRLEN_LITERAL(v)}}
 
-#if defined(UNIX) || defined(MSWIN)
+#if defined(UNIX) || defined(MSWIN) || defined(VMS)
 // Defined as signed, to return -1 on error
 struct cellsize {
     int cs_xpixel;