diff --git a/lib/fts-cycle.c b/lib/fts-cycle.c
index 8c09fb948..13b43dbdd 100644
--- a/lib/fts-cycle.c
+++ b/lib/fts-cycle.c
@@ -18,6 +18,10 @@
    along with this program; if not, write to the Free Software Foundation,
    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
 #include "cycle-check.h"
 #include "hash.h"