diff --git a/usr.bin/m4/main.c b/usr.bin/m4/main.c
--- a/usr.bin/m4/main.c
+++ b/usr.bin/m4/main.c
@@ -137,7 +137,7 @@
 	{ "popdef",       POPDTYPE },
 	{ "pushdef",      PUSDTYPE },
 	{ "dumpdef",      DUMPTYPE | NOARGS },
-	{ "shift",        SHIFTYPE | NOARGS },
+	{ "shift",        SHIFTYPE },
 	{ "translit",     TRNLTYPE },
 	{ "undefine",     UNDFTYPE },
 	{ "undivert",     UNDVTYPE | NOARGS },