diff --git a/src/starter/invokepluto.c b/src/starter/invokepluto.c
index b1bca0ec1..241bad77d 100644
--- a/src/starter/invokepluto.c
+++ b/src/starter/invokepluto.c
@@ -21,6 +21,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <errno.h>
+#include <fcntl.h>
 
 #include <freeswan.h>