diff --git a/src/cli.c b/src/cli.c
index 68dc06cd..5f8b18c9 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -33,6 +33,7 @@
 #include <netinet/udp.h>
 #include <fcntl.h>
 #include <netdb.h>
+#include <signal.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <picotls.h>