diff --git a/pkg/api/api.go b/pkg/api/api.go
index 5e361ffc6fc..c3a51fe3b31 100644
--- a/pkg/api/api.go
+++ b/pkg/api/api.go
@@ -242,6 +242,9 @@ func Respond(w http.ResponseWriter, data interface{}, warnings []error) {
 		Data:   data,
 	}
 	for _, warn := range warnings {
+		if warn == nil {
+			continue
+		}
 		resp.Warnings = append(resp.Warnings, warn.Error())
 	}
 	_ = json.NewEncoder(w).Encode(resp)