diff --git a/lang/m2/libm2/blockmove.c b/lang/m2/libm2/blockmove.c
index cdf80c551..18f2d3b5c 100644
--- a/lang/m2/libm2/blockmove.c
+++ b/lang/m2/libm2/blockmove.c
@@ -9,7 +9,7 @@
   Version:	$Header$
 */
 
-#if EM_WSIZE==EM_PSIZE
+#if _EM_WSIZE==_EM_PSIZE
 typedef unsigned pcnt;
 #else
 typedef unsigned long pcnt;