diff --git a/daemon/dtmf.c b/daemon/dtmf.c
index 783d555dd..6586a48bc 100644
--- a/daemon/dtmf.c
+++ b/daemon/dtmf.c
@@ -1,3 +1,4 @@
+#include <errno.h>
 #include "dtmf.h"
 #include "media_socket.h"
 #include "log.h"