diff --git a/cmds/statsd/src/statsd_config.proto b/cmds/statsd/src/statsd_config.proto
index 5c46a296b9bfc..aa789c799056e 100644
--- a/cmds/statsd/src/statsd_config.proto
+++ b/cmds/statsd/src/statsd_config.proto
@@ -274,6 +274,7 @@ message ValueMetric {
   optional bool use_diff = 12;
 
   enum ValueDirection {
+      UNKNOWN = 0;
       INCREASING = 1;
       DECREASING = 2;
       ANY = 3;