diff --git a/resolver/resolver-https.go b/resolver/resolver-https.go
index b0ce489b..cbf86ae8 100644
--- a/resolver/resolver-https.go
+++ b/resolver/resolver-https.go
@@ -70,9 +70,9 @@ func (hr *HTTPSResolver) Query(ctx context.Context, q *Query) (*RRCache, error)
 	if err != nil {
 		return nil, err
 	}
-	b64dns := base64.RawStdEncoding.EncodeToString(buf)
+	b64dns := base64.RawURLEncoding.EncodeToString(buf)
 
-	// Build and execute http reuqest
+	// Build and execute http request
 	url := &url.URL{
 		Scheme:     "https",
 		Host:       hr.resolver.ServerAddress,
@@ -94,6 +94,10 @@ func (hr *HTTPSResolver) Query(ctx context.Context, q *Query) (*RRCache, error)
 		_ = resp.Body.Close()
 	}()
 
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("http response code %s", resp.Status)
+	}
+
 	// Try to read the result
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {