diff --git a/spring-integration-core/src/main/java/org/springframework/integration/util/UpperBound.java b/spring-integration-core/src/main/java/org/springframework/integration/util/UpperBound.java
index c3847d6562..f8e286eb51 100644
--- a/spring-integration-core/src/main/java/org/springframework/integration/util/UpperBound.java
+++ b/spring-integration-core/src/main/java/org/springframework/integration/util/UpperBound.java
@@ -28,25 +28,29 @@ import java.util.concurrent.TimeUnit;
  * @since 2.0
  */
 public final class UpperBound {
+
 	public final Semaphore semaphore;
 
 	/**
 	 * Create an UpperBound with the given capacity. If the given capacity is less than 1
 	 * an infinite UpperBound is created.
-	 *
-	 * @param capacity
 	 */
 	public UpperBound(int capacity) {
 		this.semaphore = (capacity > 0) ? new Semaphore(capacity, true) : null;
 	}
 
 	/**
-	 * Acquires a lock on the underlying semaphore if this UpperBound is bounded and returns true
-	 * if it succeeds within the given timeout
+	 * Acquires a permit from the underlying semaphore if this UpperBound is bounded and returns
+	 * true if it succeeds within the given timeout. If the timeout is less than 0, it will block
+	 * indefinitely.
 	 */
 	public boolean tryAcquire(long timeoutInMilliseconds) {
 		if (this.semaphore != null) {
 			try {
+				if (timeoutInMilliseconds < 0) {
+					this.semaphore.acquire();
+					return true;
+				}
 				return this.semaphore.tryAcquire(timeoutInMilliseconds, TimeUnit.MILLISECONDS);
 			}
 			catch (InterruptedException e) {
@@ -66,4 +70,5 @@ public final class UpperBound {
 			this.semaphore.release();
 		}
 	}
-}
\ No newline at end of file
+
+}
diff --git a/spring-integration-core/src/test/java/org/springframework/integration/channel/PriorityChannelTests.java b/spring-integration-core/src/test/java/org/springframework/integration/channel/PriorityChannelTests.java
index ce275cf147..5467513193 100644
--- a/spring-integration-core/src/test/java/org/springframework/integration/channel/PriorityChannelTests.java
+++ b/spring-integration-core/src/test/java/org/springframework/integration/channel/PriorityChannelTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2010 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.
@@ -18,9 +18,16 @@ package org.springframework.integration.channel;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
 import java.util.Comparator;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.junit.Test;
 
@@ -113,6 +120,78 @@ public class PriorityChannelTests {
 		assertEquals("test-LOW", channel.receive(0).getPayload());
 	}
 
+	@Test
+	public void testTimeoutElapses() throws InterruptedException {
+		final PriorityChannel channel = new PriorityChannel(1);
+		final AtomicBoolean sentSecondMessage = new AtomicBoolean(false);
+		final CountDownLatch latch = new CountDownLatch(1);
+		Executor executor = Executors.newSingleThreadScheduledExecutor();
+		channel.send(new StringMessage("test-1"));
+		executor.execute(new Runnable() {
+			public void run() {
+				sentSecondMessage.set(channel.send(new StringMessage("test-2"), 10));
+				latch.countDown();
+			}
+		});
+		assertFalse(sentSecondMessage.get());
+		Thread.sleep(500);
+		Message<?> message1 = channel.receive();
+		assertNotNull(message1);
+		assertEquals("test-1", message1.getPayload());
+		latch.await(1000, TimeUnit.MILLISECONDS);
+		assertFalse(sentSecondMessage.get());
+		assertNull(channel.receive(0));
+	}
+
+	@Test
+	public void testTimeoutDoesNotElapse() throws InterruptedException {
+		final PriorityChannel channel = new PriorityChannel(1);
+		final AtomicBoolean sentSecondMessage = new AtomicBoolean(false);
+		final CountDownLatch latch = new CountDownLatch(1);
+		Executor executor = Executors.newSingleThreadScheduledExecutor();
+		channel.send(new StringMessage("test-1"));
+		executor.execute(new Runnable() {
+			public void run() {
+				sentSecondMessage.set(channel.send(new StringMessage("test-2"), 3000));
+				latch.countDown();
+			}
+		});
+		assertFalse(sentSecondMessage.get());
+		Thread.sleep(500);
+		Message<?> message1 = channel.receive();
+		assertNotNull(message1);
+		assertEquals("test-1", message1.getPayload());
+		latch.await(1000, TimeUnit.MILLISECONDS);
+		assertTrue(sentSecondMessage.get());
+		Message<?> message2 = channel.receive();
+		assertNotNull(message2);
+		assertEquals("test-2", message2.getPayload());
+	}
+
+	@Test
+	public void testIndefiniteTimeout() throws InterruptedException {
+		final PriorityChannel channel = new PriorityChannel(1);
+		final AtomicBoolean sentSecondMessage = new AtomicBoolean(false);
+		final CountDownLatch latch = new CountDownLatch(1);
+		Executor executor = Executors.newSingleThreadScheduledExecutor();
+		channel.send(new StringMessage("test-1"));
+		executor.execute(new Runnable() {
+			public void run() {
+				sentSecondMessage.set(channel.send(new StringMessage("test-2"), -1));
+				latch.countDown();
+			}
+		});
+		assertFalse(sentSecondMessage.get());
+		Message<?> message1 = channel.receive();
+		assertNotNull(message1);
+		assertEquals("test-1", message1.getPayload());
+		latch.await(1000, TimeUnit.MILLISECONDS);
+		assertTrue(sentSecondMessage.get());
+		Message<?> message2 = channel.receive();
+		assertNotNull(message2);
+		assertEquals("test-2", message2.getPayload());
+	}
+
 
 	private static Message<String> createPriorityMessage(MessagePriority priority) {
 		return MessageBuilder.withPayload("test-" + priority).setPriority(priority).build();