diff --git a/httpclient5-testing/src/test/java/org/apache/hc/client5/testing/async/TestHttpAsyncMinimalTls.java b/httpclient5-testing/src/test/java/org/apache/hc/client5/testing/async/TestHttpAsyncMinimalTls.java
new file mode 100644
index 000000000..b960e4e90
--- /dev/null
+++ b/httpclient5-testing/src/test/java/org/apache/hc/client5/testing/async/TestHttpAsyncMinimalTls.java
@@ -0,0 +1,142 @@
+/*
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+package org.apache.hc.client5.testing.async;
+
+import java.net.InetSocketAddress;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+
+import javax.net.ssl.SSLException;
+
+import org.apache.hc.client5.http.impl.async.HttpAsyncClients;
+import org.apache.hc.client5.http.impl.async.MinimalHttpAsyncClient;
+import org.apache.hc.client5.http.impl.nio.PoolingAsyncClientConnectionManagerBuilder;
+import org.apache.hc.client5.http.ssl.DefaultClientTlsStrategy;
+import org.apache.hc.client5.testing.SSLTestContexts;
+import org.apache.hc.core5.http.HttpHost;
+import org.apache.hc.core5.http.URIScheme;
+import org.apache.hc.core5.http.config.Http1Config;
+import org.apache.hc.core5.http.nio.AsyncClientEndpoint;
+import org.apache.hc.core5.http2.config.H2Config;
+import org.apache.hc.core5.io.CloseMode;
+import org.apache.hc.core5.reactor.IOReactorConfig;
+import org.apache.hc.core5.reactor.ListenerEndpoint;
+import org.apache.hc.core5.ssl.SSLContexts;
+import org.junit.Assert;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.migrationsupport.rules.EnableRuleMigrationSupport;
+import org.junit.rules.ExternalResource;
+
+@EnableRuleMigrationSupport
+public class TestHttpAsyncMinimalTls extends AbstractServerTestBase {
+
+    public TestHttpAsyncMinimalTls() {
+        super(URIScheme.HTTPS);
+    }
+
+    MinimalHttpAsyncClient httpclient;
+
+    @Rule
+    public ExternalResource clientResource = new ExternalResource() {
+
+        @Override
+        protected void after() {
+            if (httpclient != null) {
+                httpclient.close(CloseMode.GRACEFUL);
+                httpclient = null;
+            }
+        }
+
+    };
+
+    @Test
+    public void testSuccessfulTlsHandshake() throws Exception {
+        final int maxConnNo = 2;
+
+        httpclient = HttpAsyncClients.createMinimal(
+                H2Config.DEFAULT,
+                Http1Config.DEFAULT,
+                IOReactorConfig.custom()
+                        .setSoTimeout(TIMEOUT)
+                        .build(),
+                PoolingAsyncClientConnectionManagerBuilder.create()
+                        .setTlsStrategy(new DefaultClientTlsStrategy(SSLTestContexts.createClientSSLContext()))
+                        .setMaxConnPerRoute(maxConnNo)
+                        .setMaxConnTotal(maxConnNo)
+                        .build());
+
+        server.start(Http1Config.DEFAULT);
+        final Future<ListenerEndpoint> endpointFuture = server.listen(new InetSocketAddress(0));
+
+        final ListenerEndpoint listenerEndpoint = endpointFuture.get();
+        final InetSocketAddress address = (InetSocketAddress) listenerEndpoint.getAddress();
+        final HttpHost target = new HttpHost(scheme.name(), "localhost", address.getPort());
+        httpclient.start();
+
+        for (int i = 0; i < maxConnNo + 1; i++) {
+            final Future<AsyncClientEndpoint> endpointLease = httpclient.lease(target, null);
+            final AsyncClientEndpoint endpoint = endpointLease.get(5, TimeUnit.SECONDS);
+            endpoint.releaseAndDiscard();
+        }
+    }
+
+    @Test
+    public void testTlsHandshakeFailure() throws Exception {
+        final int maxConnNo = 2;
+
+        httpclient = HttpAsyncClients.createMinimal(
+                H2Config.DEFAULT,
+                Http1Config.DEFAULT,
+                IOReactorConfig.custom()
+                        .setSoTimeout(TIMEOUT)
+                        .build(),
+                PoolingAsyncClientConnectionManagerBuilder.create()
+                        .setTlsStrategy(new DefaultClientTlsStrategy(SSLContexts.createDefault()))
+                        .setMaxConnPerRoute(2)
+                        .setMaxConnTotal(2)
+                        .build());
+
+        server.start(Http1Config.DEFAULT);
+        final Future<ListenerEndpoint> endpointFuture = server.listen(new InetSocketAddress(0));
+
+        final ListenerEndpoint listenerEndpoint = endpointFuture.get();
+        final InetSocketAddress address = (InetSocketAddress) listenerEndpoint.getAddress();
+        final HttpHost target = new HttpHost(scheme.name(), "localhost", address.getPort());
+        httpclient.start();
+
+        for (int i = 0; i < maxConnNo + 1; i++) {
+            final Future<AsyncClientEndpoint> endpointLease = httpclient.lease(target, null);
+            final ExecutionException executionException = Assert.assertThrows(ExecutionException.class,
+                    () -> endpointLease.get(5, TimeUnit.SECONDS));
+            Assertions.assertInstanceOf(SSLException.class, executionException.getCause());
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/MinimalHttpAsyncClient.java b/httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/MinimalHttpAsyncClient.java
index 5521eaf53..1a4b5e601 100644
--- a/httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/MinimalHttpAsyncClient.java
+++ b/httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/MinimalHttpAsyncClient.java
@@ -164,12 +164,22 @@ public final class MinimalHttpAsyncClient extends AbstractMinimalHttpAsyncClient
 
                                         @Override
                                         public void failed(final Exception ex) {
-                                            resultFuture.failed(ex);
+                                            try {
+                                                Closer.closeQuietly(connectionEndpoint);
+                                                manager.release(connectionEndpoint, null, TimeValue.ZERO_MILLISECONDS);
+                                            } finally {
+                                                resultFuture.failed(ex);
+                                            }
                                         }
 
                                         @Override
                                         public void cancelled() {
-                                            resultFuture.cancel(true);
+                                            try {
+                                                Closer.closeQuietly(connectionEndpoint);
+                                                manager.release(connectionEndpoint, null, TimeValue.ZERO_MILLISECONDS);
+                                            } finally {
+                                                resultFuture.cancel(true);
+                                            }
                                         }
 
                                     });