diff --git a/lib/util/closefrom.c b/lib/util/closefrom.c
index d9d19456a..84c259b95 100644
--- a/lib/util/closefrom.c
+++ b/lib/util/closefrom.c
@@ -32,6 +32,7 @@
 #endif
 
 #include "sudo_compat.h"
+#include "pathnames.h"
 
 #ifndef _POSIX_OPEN_MAX
 # define _POSIX_OPEN_MAX	20