diff --git a/library/server/wsf/router/request_routing_handler.e b/library/server/wsf/router/request_routing_handler.e
index 053db16e..4cac847c 100644
--- a/library/server/wsf/router/request_routing_handler.e
+++ b/library/server/wsf/router/request_routing_handler.e
@@ -43,6 +43,9 @@ feature -- Execution
 			hdl: detachable H
 		do
 			hdl := router.dispatch_and_return_handler (req, res)
+			if hdl = Void then
+				res.put_header ({HTTP_STATUS_CODE}.not_found, <<[{HTTP_HEADER_NAMES}.header_content_length, "0"]>>)
+			end
 		end
 
 feature {NONE} -- Routing
diff --git a/library/server/wsf/router/uri_template/request_uri_template_router_i.e b/library/server/wsf/router/uri_template/request_uri_template_router_i.e
index 046b60d1..4e715e64 100644
--- a/library/server/wsf/router/uri_template/request_uri_template_router_i.e
+++ b/library/server/wsf/router/uri_template/request_uri_template_router_i.e
@@ -39,6 +39,8 @@ feature -- Registration
 		end
 
 	map_with_uri_template_and_request_methods (uri: URI_TEMPLATE; h: H; rqst_methods: detachable ARRAY [READABLE_STRING_8])
+		require
+			uri_is_valid: uri.is_valid
 		local
 			l_tpl: like {URI_TEMPLATE}.template
 			l_uri: URI_TEMPLATE