diff --git a/plugin/api/insight/metric_util.go b/plugin/api/insight/metric_util.go
index 367c6b00..7bc6ac33 100644
--- a/plugin/api/insight/metric_util.go
+++ b/plugin/api/insight/metric_util.go
@@ -385,6 +385,7 @@ func extractSomeValue(v interface{}) interface{} {
 		for _, v := range vm {
 			return extractSomeValue(v)
 		}
+		return nil
 	}
 	return v
 }