diff --git a/sysdeps/unix/grantpt.c b/sysdeps/unix/grantpt.c
index ff28179bc7..f664b9eb1b 100644
--- a/sysdeps/unix/grantpt.c
+++ b/sysdeps/unix/grantpt.c
@@ -19,6 +19,7 @@
 
 #include <assert.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <grp.h>
 #include <limits.h>
 #include <stdlib.h>