diff --git a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/fairness/ProportionRouterRpcFairnessPolicyController.java b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/fairness/ProportionRouterRpcFairnessPolicyController.java
index 71b5623901..8eeb251252 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/fairness/ProportionRouterRpcFairnessPolicyController.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/fairness/ProportionRouterRpcFairnessPolicyController.java
@@ -93,7 +93,8 @@ public boolean acquirePermit(String nsId) {
   public void releasePermit(String nsId) {
     if (contains(nsId)) {
       super.releasePermit(nsId);
+    } else {
+      super.releasePermit(DEFAULT_NS);
     }
-    super.releasePermit(DEFAULT_NS);
   }
 }