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 c196a84b56..5145749e7f 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
@@ -167,8 +167,6 @@ public abstract class JmsAccessor implements InitializingBean {
 	 * @see jakarta.jms.Connection#createSession(boolean, int)
 	 */
 	public void setSessionAcknowledgeMode(int sessionAcknowledgeMode) {
-		Assert.isTrue(sessionConstants.containsValue(sessionAcknowledgeMode),
-				"Only values of acknowledge mode constants allowed");
 		this.sessionAcknowledgeMode = sessionAcknowledgeMode;
 	}
 
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 69f4f9225a..0e300b342a 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
@@ -98,8 +98,6 @@ class JmsAccessorTests {
 
 	@Test
 	void setSessionAcknowledgeMode() {
-		assertThatIllegalArgumentException().isThrownBy(() -> accessor.setSessionAcknowledgeMode(999));
-
 		accessor.setSessionAcknowledgeMode(Session.AUTO_ACKNOWLEDGE);
 		assertThat(accessor.getSessionAcknowledgeMode()).isEqualTo(Session.AUTO_ACKNOWLEDGE);
 
@@ -113,6 +111,12 @@ class JmsAccessorTests {
 		assertThat(accessor.getSessionAcknowledgeMode()).isEqualTo(Session.SESSION_TRANSACTED);
 	}
 
+	@Test
+	void setCustomSessionAcknowledgeMode() {
+		accessor.setSessionAcknowledgeMode(999);
+		assertThat(accessor.getSessionAcknowledgeMode()).isEqualTo(999);
+	}
+
 	@Test
 	void customAcknowledgeModeIsConsideredClientAcknowledge() throws Exception {
 		Session session = mock();