diff --git a/pulsar-broker/src/main/java/org/apache/pulsar/broker/admin/impl/NamespacesBase.java b/pulsar-broker/src/main/java/org/apache/pulsar/broker/admin/impl/NamespacesBase.java
index f6d69a0b96ed8..ec9de23e6233f 100644
--- a/pulsar-broker/src/main/java/org/apache/pulsar/broker/admin/impl/NamespacesBase.java
+++ b/pulsar-broker/src/main/java/org/apache/pulsar/broker/admin/impl/NamespacesBase.java
@@ -1377,7 +1377,7 @@ protected void internalSetBacklogQuota(BacklogQuotaType backlogQuotaType, Backlo
                             "[{}] Failed to update backlog configuration"
                                     + " for namespace {}: conflicts with retention quota",
                             clientAppId(), namespaceName);
-                    new RestException(Status.PRECONDITION_FAILED,
+                    throw new RestException(Status.PRECONDITION_FAILED,
                             "Backlog Quota exceeds configured retention quota for namespace."
                                     + " Please increase retention quota and retry");
                 }
@@ -1427,7 +1427,7 @@ protected void internalSetRetention(RetentionPolicies retention) {
                 log.warn("[{}] Failed to update retention configuration"
                                 + " for namespace {}: conflicts with backlog quota",
                         clientAppId(), namespaceName);
-                new RestException(Status.PRECONDITION_FAILED,
+                throw new RestException(Status.PRECONDITION_FAILED,
                         "Retention Quota must exceed configured backlog quota for namespace.");
             }
             policies.retention_policies = retention;