diff --git a/spring-aop/src/main/java/org/springframework/aop/framework/JdkDynamicAopProxy.java b/spring-aop/src/main/java/org/springframework/aop/framework/JdkDynamicAopProxy.java
index 6d557b62b3..e5f9c08531 100644
--- a/spring-aop/src/main/java/org/springframework/aop/framework/JdkDynamicAopProxy.java
+++ b/spring-aop/src/main/java/org/springframework/aop/framework/JdkDynamicAopProxy.java
@@ -120,18 +120,39 @@ final class JdkDynamicAopProxy implements AopProxy, InvocationHandler, Serializa
 		if (logger.isTraceEnabled()) {
 			logger.trace("Creating JDK dynamic proxy: " + this.advised.getTargetSource());
 		}
-		if (classLoader == null || classLoader.getParent() == null) {
-			// JDK bootstrap loader or platform loader suggested ->
-			// use higher-level loader which can see Spring infrastructure classes
-			classLoader = getClass().getClassLoader();
-		}
-		return Proxy.newProxyInstance(classLoader, this.proxiedInterfaces, this);
+		return Proxy.newProxyInstance(determineClassLoader(classLoader), this.proxiedInterfaces, this);
 	}
 
 	@SuppressWarnings("deprecation")
 	@Override
 	public Class<?> getProxyClass(@Nullable ClassLoader classLoader) {
-		return Proxy.getProxyClass(classLoader, this.proxiedInterfaces);
+		return Proxy.getProxyClass(determineClassLoader(classLoader), this.proxiedInterfaces);
+	}
+
+	/**
+	 * Determine whether the JDK bootstrap or platform loader has been suggested ->
+	 * use higher-level loader which can see Spring infrastructure classes instead.
+	 */
+	private ClassLoader determineClassLoader(@Nullable ClassLoader classLoader) {
+		if (classLoader == null) {
+			// JDK bootstrap loader -> use spring-aop ClassLoader instead.
+			return getClass().getClassLoader();
+		}
+		if (classLoader.getParent() == null) {
+			// Potentially the JDK platform loader on JDK 9+
+			ClassLoader aopClassLoader = getClass().getClassLoader();
+			ClassLoader aopParent = aopClassLoader.getParent();
+			while (aopParent != null) {
+				if (classLoader == aopParent) {
+					// Suggested ClassLoader is ancestor of spring-aop ClassLoader
+					// -> use spring-aop ClassLoader itself instead.
+					return aopClassLoader;
+				}
+				aopParent = aopParent.getParent();
+			}
+		}
+		// Regular case: use suggested ClassLoader as-is.
+		return classLoader;
 	}
 
 	/**
diff --git a/spring-aop/src/test/java/org/springframework/aop/framework/ProxyFactoryTests.java b/spring-aop/src/test/java/org/springframework/aop/framework/ProxyFactoryTests.java
index effbed9f8d..a0f5291650 100644
--- a/spring-aop/src/test/java/org/springframework/aop/framework/ProxyFactoryTests.java
+++ b/spring-aop/src/test/java/org/springframework/aop/framework/ProxyFactoryTests.java
@@ -389,7 +389,9 @@ public class ProxyFactoryTests {
 		CharSequence target = "test";
 		ProxyFactory pf = new ProxyFactory(target);
 		ClassLoader cl = target.getClass().getClassLoader();
-		assertThat(((CharSequence) pf.getProxy(cl)).toString()).isEqualTo(target);
+		CharSequence proxy = (CharSequence) pf.getProxy(cl);
+		assertThat(proxy.toString()).isEqualTo(target);
+		assertThat(pf.getProxyClass(cl)).isSameAs(proxy.getClass());
 	}
 
 	@Test
@@ -398,7 +400,9 @@ public class ProxyFactoryTests {
 		ProxyFactory pf = new ProxyFactory(target);
 		pf.setProxyTargetClass(true);
 		ClassLoader cl = target.getClass().getClassLoader();
-		assertThat(((Date) pf.getProxy(cl)).getTime()).isEqualTo(target.getTime());
+		Date proxy = (Date) pf.getProxy(cl);
+		assertThat(proxy.getTime()).isEqualTo(target.getTime());
+		assertThat(pf.getProxyClass(cl)).isSameAs(proxy.getClass());
 	}
 
 	@Test
@@ -415,7 +419,9 @@ public class ProxyFactoryTests {
 		};
 		ProxyFactory pf = new ProxyFactory(target);
 		ClassLoader cl = Savepoint.class.getClassLoader();
-		assertThat(((Savepoint) pf.getProxy(cl)).getSavepointName()).isEqualTo("sp");
+		Savepoint proxy = (Savepoint) pf.getProxy(cl);
+		assertThat(proxy.getSavepointName()).isEqualTo("sp");
+		assertThat(pf.getProxyClass(cl)).isSameAs(proxy.getClass());
 	}
 
 
diff --git a/spring-jms/src/main/java/org/springframework/jms/support/JmsAccessor.java b/spring-jms/src/main/java/org/springframework/jms/support/JmsAccessor.java
index 1eea339744..a7a45c81d5 100644
--- a/spring-jms/src/main/java/org/springframework/jms/support/JmsAccessor.java
+++ b/spring-jms/src/main/java/org/springframework/jms/support/JmsAccessor.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -223,7 +223,10 @@ public abstract class JmsAccessor implements InitializingBean {
 	 * @see jakarta.jms.Session#CLIENT_ACKNOWLEDGE
 	 */
 	protected boolean isClientAcknowledge(Session session) throws JMSException {
-		return (session.getAcknowledgeMode() == Session.CLIENT_ACKNOWLEDGE);
+		int mode = session.getAcknowledgeMode();
+		return (mode != Session.SESSION_TRANSACTED &&
+				mode != Session.AUTO_ACKNOWLEDGE &&
+				mode != Session.DUPS_OK_ACKNOWLEDGE);
 	}
 
 }
diff --git a/spring-jms/src/test/java/org/springframework/jms/support/JmsAccessorTests.java b/spring-jms/src/test/java/org/springframework/jms/support/JmsAccessorTests.java
index 1e2f4b6676..516fc82365 100644
--- a/spring-jms/src/test/java/org/springframework/jms/support/JmsAccessorTests.java
+++ b/spring-jms/src/test/java/org/springframework/jms/support/JmsAccessorTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,24 +21,27 @@ import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
 
 /**
  * Unit tests for the {@link JmsAccessor} class.
  *
  * @author Rick Evans
  * @author Chris Beams
+ * @author Vedran Pavic
  */
-public class JmsAccessorTests {
+class JmsAccessorTests {
 
 	@Test
-	public void testChokesIfConnectionFactoryIsNotSupplied() throws Exception {
+	void testChokesIfConnectionFactoryIsNotSupplied() {
 		JmsAccessor accessor = new StubJmsAccessor();
 		assertThatIllegalArgumentException().isThrownBy(
 				accessor::afterPropertiesSet);
 	}
 
 	@Test
-	public void testSessionTransactedModeReallyDoesDefaultToFalse() throws Exception {
+	void testSessionTransactedModeReallyDoesDefaultToFalse() {
 		JmsAccessor accessor = new StubJmsAccessor();
 		assertThat(accessor.isSessionTransacted()).as("The [sessionTransacted] property of JmsAccessor must default to " +
 				"false. Change this test (and the attendant Javadoc) if you have " +
@@ -46,7 +49,7 @@ public class JmsAccessorTests {
 	}
 
 	@Test
-	public void testAcknowledgeModeReallyDoesDefaultToAutoAcknowledge() throws Exception {
+	void testAcknowledgeModeReallyDoesDefaultToAutoAcknowledge() {
 		JmsAccessor accessor = new StubJmsAccessor();
 		assertThat(accessor.getSessionAcknowledgeMode()).as("The [sessionAcknowledgeMode] property of JmsAccessor must default to " +
 				"[Session.AUTO_ACKNOWLEDGE]. Change this test (and the attendant " +
@@ -54,11 +57,18 @@ public class JmsAccessorTests {
 	}
 
 	@Test
-	public void testSetAcknowledgeModeNameChokesIfBadAckModeIsSupplied() throws Exception {
+	void testSetAcknowledgeModeNameChokesIfBadAckModeIsSupplied() {
 		assertThatIllegalArgumentException().isThrownBy(() ->
 				new StubJmsAccessor().setSessionAcknowledgeModeName("Tally ho chaps!"));
 	}
 
+	@Test
+	void testCustomAcknowledgeModeIsConsideredClientAcknowledge() throws Exception {
+		Session session = mock(Session.class);
+		given(session.getAcknowledgeMode()).willReturn(100);
+		JmsAccessor accessor = new StubJmsAccessor();
+		assertThat(accessor.isClientAcknowledge(session)).isTrue();
+	}
 
 	/**
 	 * Crummy, stub, do-nothing subclass of the JmsAccessor class for use in testing.