--- a/src/client_side.c
+++ b/src/client_side.c
@@ -92,6 +92,7 @@
 #endif
 
 #if LINUX_NETFILTER
+#include <linux/types.h>
 #include <linux/netfilter_ipv4.h>
 #endif
 
--- a/src/forward.c
+++ b/src/forward.c
@@ -37,6 +37,7 @@
 #include "squid.h"
 
 #if LINUX_NETFILTER
+#include <linux/types.h>
 #include <linux/netfilter_ipv4.h>
 #endif
 #if LINUX_TPROXY
