diff --git a/libc/unistd/exec.c b/libc/unistd/exec.c
index cbb98b3..a50185f 100644
--- a/libc/unistd/exec.c
+++ b/libc/unistd/exec.c
@@ -36,6 +36,7 @@
 #include <limits.h>
 #include <stdlib.h>
 #include <string.h>
+#include <strings.h>
 #include <stdio.h>
 #include <paths.h>
 #include <stdarg.h>