diff --git a/repos/os/include/net/udp.h b/repos/os/include/net/udp.h
index 317be6be6..031eb9d93 100644
--- a/repos/os/include/net/udp.h
+++ b/repos/os/include/net/udp.h
@@ -79,6 +79,9 @@ class Net::Udp_packet
 		void update_checksum(Ipv4_address ip_src,
 		                     Ipv4_address ip_dst);
 
+		bool checksum_error(Ipv4_address ip_src,
+		                    Ipv4_address ip_dst) const;
+
 
 		/***************
 		 ** Accessors **
diff --git a/repos/os/src/lib/net/udp.cc b/repos/os/src/lib/net/udp.cc
index e558262ae..7f70eebcc 100644
--- a/repos/os/src/lib/net/udp.cc
+++ b/repos/os/src/lib/net/udp.cc
@@ -39,3 +39,11 @@ void Net::Udp_packet::update_checksum(Ipv4_address ip_src,
 	_checksum = internet_checksum_pseudo_ip((uint16_t*)this, length(), _length,
 	                                        Ipv4_packet::Protocol::UDP, ip_src, ip_dst);
 }
+
+
+bool Net::Udp_packet::checksum_error(Ipv4_address ip_src,
+                                     Ipv4_address ip_dst) const
+{
+	return internet_checksum_pseudo_ip((uint16_t*)this, length(), _length,
+	                                   Ipv4_packet::Protocol::UDP, ip_src, ip_dst);
+}