diff --git a/src/include/replication/worker_internal.h b/src/include/replication/worker_internal.h
index 035467ce2464e2f9c32e98ed474eef7b49004baf..b8e35d4b4ddd4fe8bfa6e562216fc1755f882df8 100644
--- a/src/include/replication/worker_internal.h
+++ b/src/include/replication/worker_internal.h
@@ -12,6 +12,8 @@
 #ifndef WORKER_INTERNAL_H
 #define WORKER_INTERNAL_H
 
+#include <signal.h>
+
 #include "access/xlogdefs.h"
 #include "catalog/pg_subscription.h"
 #include "datatype/timestamp.h"