diff --git a/src/mkhdr b/src/mkhdr
index b362095e..1f801712 100644
--- a/src/mkhdr
+++ b/src/mkhdr
@@ -20,7 +20,7 @@ LDFLAGS=
 AFLAGS=
 CLEANFILES=
 NUKEFILES=
-YACC=yacc
+YACC=9yacc
 YFLAGS=-d
 LIB=
 SHORTLIB=9