diff --git a/lib/fd-reopen.c b/lib/fd-reopen.c
index 28a1b9ec4..12c55f082 100644
--- a/lib/fd-reopen.c
+++ b/lib/fd-reopen.c
@@ -18,6 +18,10 @@
 
 /* Written by Paul Eggert.  */
 
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
 #include "fd-reopen.h"
 
 #include <errno.h>