diff --git a/pulsar-proxy/src/main/java/org/apache/pulsar/proxy/server/ProxyConnection.java b/pulsar-proxy/src/main/java/org/apache/pulsar/proxy/server/ProxyConnection.java
index 5a53f6ec014a2..1e19d760c6d7b 100644
--- a/pulsar-proxy/src/main/java/org/apache/pulsar/proxy/server/ProxyConnection.java
+++ b/pulsar-proxy/src/main/java/org/apache/pulsar/proxy/server/ProxyConnection.java
@@ -19,7 +19,6 @@
 package org.apache.pulsar.proxy.server;
 
 import static com.google.common.base.Preconditions.checkArgument;
-import static com.google.common.base.Preconditions.checkState;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFutureListener;
@@ -380,7 +379,7 @@ private synchronized void completeConnect() throws PulsarClientException {
     }
 
     private void handleBrokerConnected(DirectProxyHandler directProxyHandler, CommandConnected connected) {
-        checkState(ctx.executor().inEventLoop(), "This method should be called in the event loop");
+        assert ctx.executor().inEventLoop();
         if (state == State.ProxyConnectingToBroker && ctx.channel().isOpen() && this.directProxyHandler == null) {
             this.directProxyHandler = directProxyHandler;
             state = State.ProxyConnectionToBroker;
@@ -401,7 +400,7 @@ private void handleBrokerConnected(DirectProxyHandler directProxyHandler, Comman
     }
 
     private void connectToBroker(InetSocketAddress brokerAddress) {
-        checkState(ctx.executor().inEventLoop(), "This method should be called in the event loop");
+        assert ctx.executor().inEventLoop();
         DirectProxyHandler directProxyHandler = new DirectProxyHandler(service, this);
         directProxyHandler.connect(proxyToBrokerUrl, brokerAddress, protocolVersionToAdvertise);
     }
@@ -409,10 +408,13 @@ private void connectToBroker(InetSocketAddress brokerAddress) {
     public void brokerConnected(DirectProxyHandler directProxyHandler, CommandConnected connected) {
         try {
             final CommandConnected finalConnected = new CommandConnected().copyFrom(connected);
-            ctx.executor().execute(() -> handleBrokerConnected(directProxyHandler, finalConnected));
+            handleBrokerConnected(directProxyHandler, finalConnected);
         } catch (RejectedExecutionException e) {
             LOG.error("Event loop was already closed. Closing broker connection.", e);
             directProxyHandler.close();
+        } catch (AssertionError e) {
+            LOG.error("Failed assertion, closing direct proxy handler.", e);
+            directProxyHandler.close();
         }
     }