diff --git a/protonj2-client/src/main/java/org/apache/qpid/protonj2/client/ConnectionOptions.java b/protonj2-client/src/main/java/org/apache/qpid/protonj2/client/ConnectionOptions.java
index c37e2990..04428410 100644
--- a/protonj2-client/src/main/java/org/apache/qpid/protonj2/client/ConnectionOptions.java
+++ b/protonj2-client/src/main/java/org/apache/qpid/protonj2/client/ConnectionOptions.java
@@ -26,6 +26,7 @@
 
 import org.apache.qpid.protonj2.client.exceptions.ClientOperationTimedOutException;
 import org.apache.qpid.protonj2.client.exceptions.ClientSendTimedOutException;
+import org.apache.qpid.protonj2.types.UnsignedInteger;
 import org.apache.qpid.protonj2.types.transport.Open;
 
 /**
@@ -388,7 +389,7 @@ public ConnectionOptions idleTimeout(long idleTimeout) {
      * @return this {@link ConnectionOptions} instance.
      */
     public ConnectionOptions idleTimeout(long timeout, TimeUnit units) {
-        this.idleTimeout = units.toMillis(timeout);
+        this.idleTimeout = UnsignedInteger.valueOf(units.toMillis(timeout)).longValue();;
         return this;
     }
 
diff --git a/protonj2-client/src/main/java/org/apache/qpid/protonj2/client/impl/ClientConnection.java b/protonj2-client/src/main/java/org/apache/qpid/protonj2/client/impl/ClientConnection.java
index 97ae1d67..a3057e51 100644
--- a/protonj2-client/src/main/java/org/apache/qpid/protonj2/client/impl/ClientConnection.java
+++ b/protonj2-client/src/main/java/org/apache/qpid/protonj2/client/impl/ClientConnection.java
@@ -895,7 +895,7 @@ private void initializeProtonResources(ReconnectLocation location) throws Client
         protonConnection.setLinkedResource(this);
         protonConnection.setChannelMax(options.channelMax());
         protonConnection.setMaxFrameSize(options.maxFrameSize());
-        protonConnection.setIdleTimeout((int) options.idleTimeout());
+        protonConnection.setIdleTimeout(options.idleTimeout() / 2);
         protonConnection.setOfferedCapabilities(ClientConversionSupport.toSymbolArray(options.offeredCapabilities()));
         protonConnection.setDesiredCapabilities(ClientConversionSupport.toSymbolArray(options.desiredCapabilities()));
         protonConnection.setProperties(ClientConversionSupport.toSymbolKeyedMap(options.properties()));
diff --git a/protonj2-client/src/test/java/org/apache/qpid/protonj2/client/ConnectionOptionsTest.java b/protonj2-client/src/test/java/org/apache/qpid/protonj2/client/ConnectionOptionsTest.java
index 3edda0c5..3b6f7af8 100644
--- a/protonj2-client/src/test/java/org/apache/qpid/protonj2/client/ConnectionOptionsTest.java
+++ b/protonj2-client/src/test/java/org/apache/qpid/protonj2/client/ConnectionOptionsTest.java
@@ -20,10 +20,12 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotSame;
 import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import java.util.HashMap;
 import java.util.Map;
 
+import org.apache.qpid.protonj2.types.UnsignedInteger;
 import org.junit.jupiter.api.Test;
 
 public class ConnectionOptionsTest {
@@ -37,6 +39,13 @@ public void testCreate() {
         assertNull(options.virtualHost());
     }
 
+    @Test
+    public void testSetIdleTimeoutValidesUIntRange() {
+        ConnectionOptions options = new ConnectionOptions();
+
+        assertThrows(NumberFormatException.class, () -> options.idleTimeout(UnsignedInteger.MAX_VALUE.longValue() + 1));
+    }
+
     @Test
     public void testCreateDefaultsTimeouts() {
         ConnectionOptions options = new ConnectionOptions();
diff --git a/protonj2-client/src/test/java/org/apache/qpid/protonj2/client/impl/ConnectionTest.java b/protonj2-client/src/test/java/org/apache/qpid/protonj2/client/impl/ConnectionTest.java
index 44a69b9d..e6915238 100644
--- a/protonj2-client/src/test/java/org/apache/qpid/protonj2/client/impl/ConnectionTest.java
+++ b/protonj2-client/src/test/java/org/apache/qpid/protonj2/client/impl/ConnectionTest.java
@@ -58,6 +58,7 @@
 import org.apache.qpid.protonj2.test.driver.codec.messaging.TerminusExpiryPolicy;
 import org.apache.qpid.protonj2.test.driver.codec.security.SaslCode;
 import org.apache.qpid.protonj2.test.driver.matchers.messaging.SourceMatcher;
+import org.apache.qpid.protonj2.types.UnsignedInteger;
 import org.apache.qpid.protonj2.types.messaging.AmqpValue;
 import org.apache.qpid.protonj2.types.transport.AMQPHeader;
 import org.apache.qpid.protonj2.types.transport.AmqpError;
@@ -1827,6 +1828,43 @@ public void testCreateConnectionWithEmptyVHostSendsNullValueInOpen() throws Exce
         }
     }
 
+    @Test
+    public void testCreateConnectionWithNoIdleTimeout() throws Exception {
+        doTestCreateConnectionWithIdleTimeoutSendsExpectedValue(0, 0);
+    }
+
+    @Test
+    public void testCreateConnectionWithHalfIdleTimeout() throws Exception {
+        doTestCreateConnectionWithIdleTimeoutSendsExpectedValue(10_000, 5_000);
+    }
+
+    @Test
+    public void testCreateConnectionWithHalfLargeIdleTimeout() throws Exception {
+        doTestCreateConnectionWithIdleTimeoutSendsExpectedValue(UnsignedInteger.MAX_VALUE.longValue(), UnsignedInteger.MAX_VALUE.longValue() / 2);
+    }
+
+    private void doTestCreateConnectionWithIdleTimeoutSendsExpectedValue(long setValue, long expectedValue) throws Exception {
+        try (ProtonTestServer peer = new ProtonTestServer(testServerOptions())) {
+            peer.expectSASLAnonymousConnect();
+            peer.expectOpen().withIdleTimeOut(expectedValue).respond();
+            peer.expectClose().respond();
+            peer.start();
+
+            URI remoteURI = peer.getServerURI();
+
+            LOG.info("Connect test started, peer listening on: {}", remoteURI);
+
+            Client container = Client.create();
+            ConnectionOptions options = connectionOptions().idleTimeout(setValue);
+            Connection connection = container.connect(remoteURI.getHost(), remoteURI.getPort(), options);
+
+            connection.openFuture().get(10, TimeUnit.SECONDS);
+            connection.closeAsync().get(10, TimeUnit.SECONDS);
+
+            peer.waitForScriptToComplete(5, TimeUnit.SECONDS);
+        }
+    }
+
     @Disabled("Disabled due to requirement of hard coded port")
     @Test
     public void testLocalPortOption() throws Exception {