diff --git a/include/haproxy/signal.h b/include/haproxy/signal.h
index 763cfb0be..331b7fdc6 100644
--- a/include/haproxy/signal.h
+++ b/include/haproxy/signal.h
@@ -11,6 +11,9 @@
  *
  */
 
+#ifndef _HAPROXY_SIGNAL_H
+#define _HAPROXY_SIGNAL_H
+
 #include <signal.h>
 
 #include <haproxy/api.h>
@@ -39,6 +42,8 @@ static inline void signal_process_queue()
 		__signal_process_queue();
 }
 
+#endif /* _HAPROXY_SIGNAL_H */
+
 /*
  * Local variables:
  *  c-indent-level: 8