diff --git a/sys/conf/kern.post.mk b/sys/conf/kern.post.mk
index 7bab75bd2ca..a225c948688 100644
--- a/sys/conf/kern.post.mk
+++ b/sys/conf/kern.post.mk
@@ -116,7 +116,7 @@ hack.So: Makefile
 ./assym.s: assym.s
 
 assym.s: $S/kern/genassym.sh genassym.o
-	NM=${NM} sh $S/kern/genassym.sh genassym.o > ${.TARGET}
+	NM="${NM}" sh $S/kern/genassym.sh genassym.o > ${.TARGET}
 
 genassym.o: $S/$M/$M/genassym.c
 	${CC} -c ${CFLAGS:N-fno-common} $S/$M/$M/genassym.c