diff --git a/src/analyzer/protocol/tcp/TCP_Flags.h b/src/analyzer/protocol/tcp/TCP_Flags.h
index 327d95c189..b971a3c13f 100644
--- a/src/analyzer/protocol/tcp/TCP_Flags.h
+++ b/src/analyzer/protocol/tcp/TCP_Flags.h
@@ -1,5 +1,9 @@
 #pragma once
 
+#include <sys/types.h>
+#include <netinet/tcp.h>
+#include <string>
+
 namespace zeek::analyzer::tcp {
 
 class TCP_Flags {