diff --git a/gnu/usr.bin/sort/Makefile b/gnu/usr.bin/sort/Makefile
index 79d53281ece..2b116183792 100644
--- a/gnu/usr.bin/sort/Makefile
+++ b/gnu/usr.bin/sort/Makefile
@@ -23,6 +23,7 @@ SRCS=   sort.c \
 	strnlen.c \
 	umaxtostr.c \
 	version-etc.c \
+	xalloc-die.c \
 	xmalloc.c \
 	xmemcoll.c \
 	xstrtoul.c \