diff --git a/expr/http_endpoint.go b/expr/http_endpoint.go
index 9f84995116..774a3a9f78 100644
--- a/expr/http_endpoint.go
+++ b/expr/http_endpoint.go
@@ -131,6 +131,9 @@ func (e *HTTPEndpointExpr) PathParams() *MappedAttributeExpr {
 	for _, r := range e.Routes {
 		for _, p := range r.Params() {
 			att := pat.Find(p)
+			if att == nil {
+				continue
+			}
 			obj.Set(p, att)
 			if e.Params.IsRequired(p) {
 				v.AddRequired(p)