diff --git a/babeld/route.h b/babeld/route.h
index e38f157..c08332a 100644
--- a/babeld/route.h
+++ b/babeld/route.h
@@ -37,6 +37,9 @@
 THE SOFTWARE.
 */
 
+#ifndef BABEL_ROUTE_H
+#define BABEL_ROUTE_H
+
 #include "babel_interface.h"
 #include "source.h"
 
@@ -102,3 +105,5 @@
 
 void babel_uninstall_all_routes(void);
 struct babel_route *babel_route_get_by_source(struct source *src);
+
+#endif