diff --git a/activemq-client/src/main/java/org/apache/activemq/ActiveMQConnection.java b/activemq-client/src/main/java/org/apache/activemq/ActiveMQConnection.java
index 900938ec04c..71b5192fa09 100644
--- a/activemq-client/src/main/java/org/apache/activemq/ActiveMQConnection.java
+++ b/activemq-client/src/main/java/org/apache/activemq/ActiveMQConnection.java
@@ -147,6 +147,8 @@ public class ActiveMQConnection implements Connection, TopicConnection, QueueCon
      * This strictly rejects non-standard property types such as Character, Map, and List.
      */
     private boolean strictCompliance = false;
+    // set when the client identifier came from the connection factory configuration
+    private boolean adminConfiguredClientID = false;
 
     private boolean disableTimeStampsByDefault;
     private boolean optimizedMessageDispatch = true;
@@ -463,6 +465,12 @@ public void setClientID(String newClientID) throws JMSException {
             throw new IllegalStateException("The clientID has already been set");
         }
 
+        // The specification forbids overriding an administratively configured client
+        // identifier; ActiveMQ has always allowed it, so enforce under strict compliance.
+        if (this.adminConfiguredClientID && this.strictCompliance) {
+            throw new IllegalStateException("The clientID was administratively configured and cannot be changed");
+        }
+
         if (this.isConnectionInfoSentToBroker) {
             throw new IllegalStateException("Setting clientID on a used Connection is not allowed");
         }
@@ -479,6 +487,7 @@ public void setClientID(String newClientID) throws JMSException {
     public void setDefaultClientID(String clientID) throws JMSException {
         this.info.setClientId(clientID);
         this.userSpecifiedClientID = true;
+        this.adminConfiguredClientID = true;
     }
 
     /**
@@ -1566,6 +1575,21 @@ protected synchronized void checkClosed() throws JMSException {
         }
     }
 
+    /**
+     * Validates this connection's credentials with the broker using a throwaway
+     * ConnectionInfo that is removed again immediately. The connection's own
+     * ConnectionInfo is left unsent, so setClientID() remains possible afterwards
+     * as the specification requires. Used by the factory under strictCompliance
+     * so createConnection fails fast with JMSSecurityException on bad credentials.
+     */
+    protected void authenticate() throws JMSException {
+        var probe = info.copy();
+        probe.setConnectionId(new ConnectionId(info.getConnectionId().getValue() + ":auth"));
+        probe.setClientId(clientIdGenerator.generateId());
+        syncSendPacket(probe, getConnectResponseTimeout());
+        asyncSendPacket(probe.createRemoveCommand());
+    }
+
     /**
      * Send the ConnectionInfo to the Broker
      *
diff --git a/activemq-client/src/main/java/org/apache/activemq/ActiveMQConnectionFactory.java b/activemq-client/src/main/java/org/apache/activemq/ActiveMQConnectionFactory.java
index 93cfb20d309..2b1f9ac4c09 100644
--- a/activemq-client/src/main/java/org/apache/activemq/ActiveMQConnectionFactory.java
+++ b/activemq-client/src/main/java/org/apache/activemq/ActiveMQConnectionFactory.java
@@ -308,6 +308,7 @@ public JMSContext createContext(String userName, String password) {
      */
     @Override
     public JMSContext createContext(String userName, String password, int sessionMode) {
+        ActiveMQSession.validateSessionMode(sessionMode);
         try {
             return new ActiveMQContext(createActiveMQConnection(userName, password), sessionMode);
         } catch (JMSException e) {
@@ -320,6 +321,7 @@ public JMSContext createContext(String userName, String password, int sessionMod
      */
     @Override
     public JMSContext createContext(int sessionMode) {
+        ActiveMQSession.validateSessionMode(sessionMode);
         try {
             return new ActiveMQContext(createActiveMQConnection(getUserName(), getPassword()), sessionMode);
         } catch (JMSException e) {
@@ -398,6 +400,15 @@ protected ActiveMQConnection createActiveMQConnection(String userName, String pa
                 connection.setDefaultClientID(clientID);
             }
 
+            // Jakarta Messaging expects createConnection/createContext to authenticate
+            // the caller immediately (JMSSecurityException on bad credentials). ActiveMQ
+            // historically defers the ConnectionInfo exchange until first use, so the
+            // eager check is only performed under strictCompliance, and it uses a probe
+            // so the connection's own identity stays unset for a later setClientID().
+            if (isStrictCompliance()) {
+                connection.authenticate();
+            }
+
             return connection;
         } catch (JMSException e) {
             // Clean up!
diff --git a/activemq-client/src/main/java/org/apache/activemq/ActiveMQContext.java b/activemq-client/src/main/java/org/apache/activemq/ActiveMQContext.java
index 72ef853313b..0f9bf543a31 100644
--- a/activemq-client/src/main/java/org/apache/activemq/ActiveMQContext.java
+++ b/activemq-client/src/main/java/org/apache/activemq/ActiveMQContext.java
@@ -97,6 +97,7 @@ public JMSContext createContext(int sessionMode) {
         if(connectionCounter.get() == 0l) {
             throw new JMSRuntimeException("Context already closed");
         }
+        ActiveMQSession.validateSessionMode(sessionMode);
 
         connectionCounter.incrementAndGet();
         return new ActiveMQContext(activemqConnection, sessionMode, connectionCounter);
diff --git a/activemq-client/src/main/java/org/apache/activemq/ActiveMQSession.java b/activemq-client/src/main/java/org/apache/activemq/ActiveMQSession.java
index dc206850415..ae5369821bd 100644
--- a/activemq-client/src/main/java/org/apache/activemq/ActiveMQSession.java
+++ b/activemq-client/src/main/java/org/apache/activemq/ActiveMQSession.java
@@ -36,6 +36,7 @@
 import jakarta.jms.InvalidDestinationException;
 import jakarta.jms.InvalidSelectorException;
 import jakarta.jms.JMSException;
+import jakarta.jms.JMSRuntimeException;
 import jakarta.jms.MapMessage;
 import jakarta.jms.Message;
 import jakarta.jms.MessageConsumer;
@@ -197,6 +198,17 @@ public class ActiveMQSession implements Session, QueueSession, TopicSession, Sta
     public static final int INDIVIDUAL_ACKNOWLEDGE = 4;
     public static final int MAX_ACK_CONSTANT = INDIVIDUAL_ACKNOWLEDGE;
 
+    /**
+     * Rejects a JMSContext session mode outside the four Jakarta Messaging modes
+     * and ActiveMQ's INDIVIDUAL_ACKNOWLEDGE extension, as the specification
+     * requires a JMSRuntimeException for an invalid mode.
+     */
+    static void validateSessionMode(int sessionMode) {
+        if (sessionMode < Session.SESSION_TRANSACTED || sessionMode > MAX_ACK_CONSTANT) {
+            throw new JMSRuntimeException("Invalid session mode: " + sessionMode);
+        }
+    }
+
     public static interface DeliveryListener {
         void beforeDelivery(ActiveMQSession session, Message msg);
 
diff --git a/activemq-client/src/main/java/org/apache/activemq/command/ActiveMQBytesMessage.java b/activemq-client/src/main/java/org/apache/activemq/command/ActiveMQBytesMessage.java
index 822d7643652..2e177af95b6 100644
--- a/activemq-client/src/main/java/org/apache/activemq/command/ActiveMQBytesMessage.java
+++ b/activemq-client/src/main/java/org/apache/activemq/command/ActiveMQBytesMessage.java
@@ -965,7 +965,10 @@ protected void doCompress() throws IOException {
     @Override
     @SuppressWarnings("unchecked")
     public boolean isBodyAssignableTo(Class c) {
-        return getContent() == null || c.isAssignableFrom(byte[].class);
+        // Bytes written in write-only mode sit in bytesOut until stored, so a null
+        // content alone does not mean the message has no body.
+        var hasBody = getContent() != null || (bytesOut != null && bytesOut.size() > 0);
+        return !hasBody || c.isAssignableFrom(byte[].class);
     }
 
     @SuppressWarnings("unchecked")
diff --git a/activemq-client/src/main/java/org/apache/activemq/command/ActiveMQMapMessage.java b/activemq-client/src/main/java/org/apache/activemq/command/ActiveMQMapMessage.java
index 6f5473f659b..576a4a65fc1 100644
--- a/activemq-client/src/main/java/org/apache/activemq/command/ActiveMQMapMessage.java
+++ b/activemq-client/src/main/java/org/apache/activemq/command/ActiveMQMapMessage.java
@@ -793,8 +793,9 @@ public void setBytes(String name, byte[] value, int offset, int length) throws J
     public void setObject(String name, Object value) throws JMSException {
         initializeWriting();
         if (value != null) {
-            // byte[] not allowed on properties
-            if (!(value instanceof byte[])) {
+            // byte[] and Character are valid MapMessage body types (MapMessage#setBytes,
+            // #setChar) but not valid property types, so they bypass the property check
+            if (!(value instanceof byte[]) && !(value instanceof Character)) {
                 checkValidObject(value);
             }
             put(name, value);
diff --git a/activemq-tooling/activemq-jakarta-messaging-tck/pom.xml b/activemq-tooling/activemq-jakarta-messaging-tck/pom.xml
index 1a6ebae848f..36577f48953 100644
--- a/activemq-tooling/activemq-jakarta-messaging-tck/pom.xml
+++ b/activemq-tooling/activemq-jakarta-messaging-tck/pom.xml
@@ -43,6 +43,11 @@
       <groupId>org.apache.activemq</groupId>
       <artifactId>activemq-kahadb-store</artifactId>
     </dependency>
+    <dependency>
+      <!-- SimpleAuthenticationPlugin principals, used to reject bad credentials -->
+      <groupId>org.apache.activemq</groupId>
+      <artifactId>activemq-jaas</artifactId>
+    </dependency>
     <dependency>
       <groupId>org.apache.logging.log4j</groupId>
       <artifactId>log4j-slf4j2-impl</artifactId>
diff --git a/activemq-tooling/activemq-jakarta-messaging-tck/src/main/java/org/apache/activemq/tck/JNDIInitialContextFactory.java b/activemq-tooling/activemq-jakarta-messaging-tck/src/main/java/org/apache/activemq/tck/JNDIInitialContextFactory.java
index a95a86eeb23..66dccd6edaf 100644
--- a/activemq-tooling/activemq-jakarta-messaging-tck/src/main/java/org/apache/activemq/tck/JNDIInitialContextFactory.java
+++ b/activemq-tooling/activemq-jakarta-messaging-tck/src/main/java/org/apache/activemq/tck/JNDIInitialContextFactory.java
@@ -28,6 +28,9 @@
 import javax.naming.NamingException;
 import javax.naming.spi.InitialContextFactory;
 
+import org.apache.activemq.broker.BrokerPlugin;
+import org.apache.activemq.security.AuthenticationUser;
+import org.apache.activemq.security.SimpleAuthenticationPlugin;
 import org.apache.activemq.ActiveMQConnectionFactory;
 import org.apache.activemq.broker.BrokerService;
 import org.apache.activemq.command.ActiveMQQueue;
@@ -97,6 +100,11 @@ public Context getInitialContext(final Hashtable<?, ?> environment) throws Namin
     private static ActiveMQConnectionFactory createConnectionFactory(final String clientId) {
         final ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory(BROKER_URL);
         factory.setNestedMapAndListEnabled(false);
+        // The TCK asserts strict Jakarta Messaging semantics that ActiveMQ relaxes by
+        // default for backwards compatibility: eager authentication on
+        // createConnection/createContext, the administratively configured client
+        // identifier, and the strict message property rules.
+        factory.setStrictCompliance(true);
         if (clientId != null) {
             factory.setClientID(clientId);
         }
@@ -117,6 +125,14 @@ private static void ensureBrokerStarted() {
                 bs.setPersistent(false);
                 bs.setUseJmx(false);
                 bs.setAdvisorySupport(false);
+                // The TCK expects invalid credentials to be rejected (JMSSecurityException
+                // from createConnection, JMSSecurityRuntimeException from createContext).
+                // Authenticate the ts.jte user and keep anonymous access for the many
+                // tests that connect without credentials.
+                var authentication = new SimpleAuthenticationPlugin(
+                    java.util.List.of(new AuthenticationUser("guest", "guest", "users")));
+                authentication.setAnonymousAccessAllowed(true);
+                bs.setPlugins(new BrokerPlugin[] {authentication});
                 bs.start();
                 bs.waitUntilStarted();
                 broker = bs;
diff --git a/activemq-unit-tests/src/test/java/org/apache/activemq/ActiveMQMessagePropertyTest.java b/activemq-unit-tests/src/test/java/org/apache/activemq/ActiveMQMessagePropertyTest.java
index 1180c825a9a..ce8a041be5e 100644
--- a/activemq-unit-tests/src/test/java/org/apache/activemq/ActiveMQMessagePropertyTest.java
+++ b/activemq-unit-tests/src/test/java/org/apache/activemq/ActiveMQMessagePropertyTest.java
@@ -22,6 +22,7 @@
 import org.junit.Test;
 
 import jakarta.jms.Connection;
+import jakarta.jms.MapMessage;
 import jakarta.jms.Message;
 import jakarta.jms.MessageFormatException;
 import jakarta.jms.Session;
@@ -108,4 +109,49 @@ public void testLegacyModeStillAllowsCharacter() throws Exception {
             assertEquals('A', message.getObjectProperty("charProp"));
         }
     }
+
+    @Test
+    public void testStrictComplianceAllowsCharacterInMapMessageBody() throws Exception {
+        var factory = new ActiveMQConnectionFactory(connectionUri);
+        factory.setStrictCompliance(true);
+
+        try (var connection = factory.createConnection();
+             var session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE)) {
+
+            // MapMessage bodies support char per the spec; only message properties
+            // exclude Character under strict compliance
+            var message = session.createMapMessage();
+            message.setChar("charEntry", 'A');
+            message.setObject("charObject", 'B');
+            assertEquals('A', message.getChar("charEntry"));
+            assertEquals('B', message.getObject("charObject"));
+
+            try {
+                message.setObjectProperty("charProp", 'C');
+                fail("Character properties must still be rejected under strict compliance");
+            } catch (MessageFormatException expected) {
+            }
+        }
+    }
+
+    @Test
+    public void testGetBodyOnWriteOnlyBytesMessageChecksType() throws Exception {
+        var factory = new ActiveMQConnectionFactory(connectionUri);
+
+        try (var connection = factory.createConnection();
+             var session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE)) {
+
+            var message = session.createBytesMessage();
+            message.writeBytes(new byte[] {1, 2, 3});
+
+            // bytes written but not yet stored are still a body: a non-byte[] type
+            // must be rejected even while the message is in write-only mode
+            try {
+                message.getBody(StringBuffer.class);
+                fail("Expected MessageFormatException for a non byte[] body type");
+            } catch (MessageFormatException expected) {
+            }
+            assertEquals(3, message.getBody(byte[].class).length);
+        }
+    }
 }
diff --git a/activemq-unit-tests/src/test/java/org/apache/activemq/StrictComplianceAuthenticationTest.java b/activemq-unit-tests/src/test/java/org/apache/activemq/StrictComplianceAuthenticationTest.java
new file mode 100644
index 00000000000..6f91e5c696b
--- /dev/null
+++ b/activemq-unit-tests/src/test/java/org/apache/activemq/StrictComplianceAuthenticationTest.java
@@ -0,0 +1,137 @@
+/**
+ * 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.
+ */
+package org.apache.activemq;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.fail;
+
+import java.util.ArrayList;
+
+import jakarta.jms.JMSException;
+import jakarta.jms.JMSSecurityException;
+import jakarta.jms.JMSSecurityRuntimeException;
+
+import org.apache.activemq.broker.BrokerPlugin;
+import org.apache.activemq.broker.BrokerService;
+import org.apache.activemq.security.AuthenticationUser;
+import org.apache.activemq.security.SimpleAuthenticationPlugin;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Jakarta Messaging expects createConnection and createContext to authenticate
+ * the caller immediately. ActiveMQ defers the ConnectionInfo exchange until
+ * first use, so the eager handshake is enabled by strictCompliance.
+ */
+public class StrictComplianceAuthenticationTest {
+
+    private BrokerService broker;
+    private String connectionUri;
+
+    @Before
+    public void setUp() throws Exception {
+        broker = new BrokerService();
+        broker.setPersistent(false);
+        broker.setUseJmx(false);
+        broker.setAdvisorySupport(false);
+        var users = new ArrayList<AuthenticationUser>();
+        users.add(new AuthenticationUser("system", "manager", "users,admins"));
+        broker.setPlugins(new BrokerPlugin[] {new SimpleAuthenticationPlugin(users)});
+        broker.addConnector("tcp://localhost:0");
+        broker.start();
+        broker.waitUntilStarted();
+        connectionUri = broker.getTransportConnectors().get(0).getPublishableConnectString();
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        if (broker != null) {
+            broker.stop();
+            broker.waitUntilStopped();
+        }
+    }
+
+    @Test(timeout = 60000)
+    public void testStrictCreateConnectionRejectsBadCredentialsImmediately() throws Exception {
+        var factory = new ActiveMQConnectionFactory(connectionUri);
+        factory.setStrictCompliance(true);
+
+        try {
+            factory.createConnection("invalid", "credentials");
+            fail("Expected JMSSecurityException from createConnection");
+        } catch (JMSSecurityException expected) {
+        }
+
+        try (var connection = factory.createConnection("system", "manager")) {
+            connection.start();
+            assertNotNull(connection.getClientID());
+        }
+    }
+
+    @Test(timeout = 60000)
+    public void testStrictCreateContextRejectsBadCredentialsImmediately() throws Exception {
+        var factory = new ActiveMQConnectionFactory(connectionUri);
+        factory.setStrictCompliance(true);
+
+        try {
+            factory.createContext("invalid", "credentials");
+            fail("Expected JMSSecurityRuntimeException from createContext");
+        } catch (JMSSecurityRuntimeException expected) {
+        }
+
+        try (var context = factory.createContext("system", "manager")) {
+            context.start();
+            assertNotNull(context.getClientID());
+        }
+    }
+
+    @Test(timeout = 60000)
+    public void testStrictCreateConnectionStillAllowsSetClientID() throws Exception {
+        var factory = new ActiveMQConnectionFactory(connectionUri);
+        factory.setStrictCompliance(true);
+
+        // the spec-mandated sequence: set the client identifier immediately after
+        // creation, before any other action; eager authentication must not
+        // consume the connection's identity
+        try (var connection = factory.createConnection("system", "manager")) {
+            connection.setClientID("strict-client");
+            connection.start();
+            assertEquals("strict-client", connection.getClientID());
+        }
+    }
+
+    @Test(timeout = 60000)
+    public void testLegacyCreateConnectionDefersAuthenticationToStart() throws Exception {
+        var factory = new ActiveMQConnectionFactory(connectionUri);
+
+        // Default strictCompliance = false: creation succeeds, the failure surfaces
+        // when the connection first talks to the broker
+        var connection = factory.createConnection("invalid", "credentials");
+        try {
+            connection.start();
+            fail("Expected JMSSecurityException on start");
+        } catch (JMSSecurityException expected) {
+        } catch (JMSException disposed) {
+            // the failed connection may be torn down asynchronously before the
+            // security exception reaches start(); either form indicates rejection
+        } finally {
+            try { connection.close(); } catch (Exception ignored) {}
+        }
+    }
+}
diff --git a/activemq-unit-tests/src/test/java/org/apache/activemq/StrictComplianceClientIDTest.java b/activemq-unit-tests/src/test/java/org/apache/activemq/StrictComplianceClientIDTest.java
new file mode 100644
index 00000000000..a78b9981dda
--- /dev/null
+++ b/activemq-unit-tests/src/test/java/org/apache/activemq/StrictComplianceClientIDTest.java
@@ -0,0 +1,94 @@
+/**
+ * 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.
+ */
+package org.apache.activemq;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import jakarta.jms.IllegalStateRuntimeException;
+
+import org.apache.activemq.broker.BrokerService;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * A client identifier configured on the connection factory is administratively
+ * configured; the specification forbids the application from overriding it.
+ * ActiveMQ has always allowed the override, so enforcement is tied to
+ * strictCompliance.
+ */
+public class StrictComplianceClientIDTest {
+
+    private BrokerService broker;
+
+    @Before
+    public void setUp() throws Exception {
+        broker = new BrokerService();
+        broker.setPersistent(false);
+        broker.setUseJmx(false);
+        broker.setAdvisorySupport(false);
+        broker.addConnector("vm://localhost");
+        broker.start();
+        broker.waitUntilStarted();
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        if (broker != null) {
+            broker.stop();
+            broker.waitUntilStopped();
+        }
+    }
+
+    @Test(timeout = 60000)
+    public void testStrictRejectsOverridingAdminConfiguredClientID() throws Exception {
+        var factory = new ActiveMQConnectionFactory("vm://localhost");
+        factory.setStrictCompliance(true);
+        factory.setClientID("admin-configured");
+
+        try (var connection = factory.createConnection()) {
+            try {
+                connection.setClientID("application-override");
+                fail("Expected IllegalStateException overriding an administratively configured clientID");
+            } catch (jakarta.jms.IllegalStateException expected) {
+            }
+            assertEquals("admin-configured", connection.getClientID());
+        }
+
+        try (var context = factory.createContext()) {
+            try {
+                context.setClientID("application-override");
+                fail("Expected IllegalStateRuntimeException overriding an administratively configured clientID");
+            } catch (IllegalStateRuntimeException expected) {
+            }
+            assertEquals("admin-configured", context.getClientID());
+        }
+    }
+
+    @Test(timeout = 60000)
+    public void testLegacyAllowsOverridingAdminConfiguredClientID() throws Exception {
+        var factory = new ActiveMQConnectionFactory("vm://localhost");
+        factory.setClientID("admin-configured");
+
+        // Default strictCompliance = false keeps the historical override behavior
+        try (var connection = factory.createConnection()) {
+            connection.setClientID("application-override");
+            assertEquals("application-override", connection.getClientID());
+        }
+    }
+}
diff --git a/activemq-unit-tests/src/test/java/org/apache/activemq/jms2/ActiveMQJMS2ContextTest.java b/activemq-unit-tests/src/test/java/org/apache/activemq/jms2/ActiveMQJMS2ContextTest.java
index 5334546aa56..5a792289a9f 100644
--- a/activemq-unit-tests/src/test/java/org/apache/activemq/jms2/ActiveMQJMS2ContextTest.java
+++ b/activemq-unit-tests/src/test/java/org/apache/activemq/jms2/ActiveMQJMS2ContextTest.java
@@ -60,6 +60,32 @@ public void testConnectionFactoryCreateContext() {
         }
     }
 
+    @Test
+    public void testCreateContextRejectsInvalidSessionMode() {
+        for (int invalidMode : new int[] {-1, 5, 99}) {
+            try {
+                activemqConnectionFactory.createContext(invalidMode).close();
+                fail("Expected JMSRuntimeException for session mode " + invalidMode);
+            } catch (JMSRuntimeException expected) {
+            }
+            try {
+                activemqConnectionFactory.createContext(DEFAULT_JMS_USER, DEFAULT_JMS_PASS, invalidMode).close();
+                fail("Expected JMSRuntimeException for session mode " + invalidMode);
+            } catch (JMSRuntimeException expected) {
+            }
+        }
+
+        // the ActiveMQ INDIVIDUAL_ACKNOWLEDGE extension remains a valid mode
+        try (var jmsContext = activemqConnectionFactory.createContext(org.apache.activemq.ActiveMQSession.INDIVIDUAL_ACKNOWLEDGE)) {
+            assertEquals(org.apache.activemq.ActiveMQSession.INDIVIDUAL_ACKNOWLEDGE, jmsContext.getSessionMode());
+            try {
+                jmsContext.createContext(42).close();
+                fail("Expected JMSRuntimeException for child context session mode 42");
+            } catch (JMSRuntimeException expected) {
+            }
+        }
+    }
+
     @Test
     public void testConnectionFactoryCreateContextSession() {
         try(JMSContext jmsContext = activemqConnectionFactory.createContext(Session.AUTO_ACKNOWLEDGE)) {