diff --git a/promql/parser/parse.go b/promql/parser/parse.go
index 79424dd98d..6e9bbe23a5 100644
--- a/promql/parser/parse.go
+++ b/promql/parser/parse.go
@@ -169,6 +169,7 @@ func newParser(input string) *parser {
 
 	p.injecting = false
 	p.parseErrors = nil
+	p.generatedParserResult = nil
 
 	// Clear lexer struct before reusing.
 	p.lex = Lexer{
diff --git a/web/api/v1/api.go b/web/api/v1/api.go
index a11686a3f9..b44dc86cee 100644
--- a/web/api/v1/api.go
+++ b/web/api/v1/api.go
@@ -249,6 +249,9 @@ func (api *API) Register(r *route.Router) {
 		hf := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			httputil.SetCORS(w, api.CORSOrigin, r)
 			result := f(r)
+			if result.finalizer != nil {
+				defer result.finalizer()
+			}
 			if result.err != nil {
 				api.respondError(w, result.err, result.data)
 			} else if result.data != nil {
@@ -256,9 +259,6 @@ func (api *API) Register(r *route.Router) {
 			} else {
 				w.WriteHeader(http.StatusNoContent)
 			}
-			if result.finalizer != nil {
-				result.finalizer()
-			}
 		})
 		return api.ready(httputil.CompressionHandler{
 			Handler: hf,
diff --git a/web/federate.go b/web/federate.go
index 93c9aece36..19ad59cdb3 100644
--- a/web/federate.go
+++ b/web/federate.go
@@ -44,6 +44,10 @@ var (
 	})
 )
 
+func registerFederationMetrics(r prometheus.Registerer) {
+	r.MustRegister(federationWarnings, federationErrors)
+}
+
 func (h *Handler) federation(w http.ResponseWriter, req *http.Request) {
 	h.mtx.RLock()
 	defer h.mtx.RUnlock()
diff --git a/web/web.go b/web/web.go
index 21fc02158a..48fc62c8cd 100644
--- a/web/web.go
+++ b/web/web.go
@@ -139,6 +139,7 @@ func newMetrics(r prometheus.Registerer) *metrics {
 
 	if r != nil {
 		r.MustRegister(m.requestCounter, m.requestDuration, m.responseSize)
+		registerFederationMetrics(r)
 	}
 	return m
 }