diff --git a/_data/rules.yml b/_data/rules.yml
index 81d3806..2139a74 100644
--- a/_data/rules.yml
+++ b/_data/rules.yml
@@ -737,7 +737,7 @@ groups:
                 severity: critical
               - name: MongoDB replication headroom
                 description: MongoDB replication headroom is <= 0
-                query: '(avg(mongodb_mongod_replset_oplog_tail_timestamp - mongodb_mongod_replset_oplog_head_timestamp) - (avg(mongodb_mongod_replset_member_optime_date{state="PRIMARY"}) - avg(mongodb_mongod_replset_member_optime_date{state="SECONDARY"}))) <= 0'
+                query: '(avg(mongodb_mongod_replset_oplog_head_timestamp - mongodb_mongod_replset_oplog_tail_timestamp) - (avg(mongodb_mongod_replset_member_optime_date{state="PRIMARY"}) - avg(mongodb_mongod_replset_member_optime_date{state="SECONDARY"}))) <= 0'
                 severity: critical
               - name: MongoDB number cursors open
                 description: Too many cursors opened by MongoDB for clients (> 10k)