diff --git a/src/main/java/com/microsoft/azure/proton/transport/ws/impl/WebSocketHandlerImpl.java b/src/main/java/com/microsoft/azure/proton/transport/ws/impl/WebSocketHandlerImpl.java
index bcfaddd..e8e1bb9 100644
--- a/src/main/java/com/microsoft/azure/proton/transport/ws/impl/WebSocketHandlerImpl.java
+++ b/src/main/java/com/microsoft/azure/proton/transport/ws/impl/WebSocketHandlerImpl.java
@@ -64,7 +64,9 @@ public Boolean validateUpgradeReply(ByteBuffer buffer) {
                 buffer.get(data);
 
                 retVal = webSocketUpgrade.validateUpgradeReply(data);
-                webSocketUpgrade = null;
+                if (retVal) {
+                	webSocketUpgrade = null;
+                }
             }
         }
 
diff --git a/src/main/java/com/microsoft/azure/proton/transport/ws/impl/WebSocketImpl.java b/src/main/java/com/microsoft/azure/proton/transport/ws/impl/WebSocketImpl.java
index c7253d7..ec6f2e4 100644
--- a/src/main/java/com/microsoft/azure/proton/transport/ws/impl/WebSocketImpl.java
+++ b/src/main/java/com/microsoft/azure/proton/transport/ws/impl/WebSocketImpl.java
@@ -26,7 +26,12 @@
 import org.apache.qpid.proton.engine.impl.TransportOutput;
 import org.apache.qpid.proton.engine.impl.TransportWrapper;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 public class WebSocketImpl implements WebSocket, TransportLayer {
+    private static final Logger TRACE_LOGGER = LoggerFactory.getLogger(WebSocketImpl.class);
+
     private int maxFrameSize = (4 * 1024) + (16 * WebSocketHeader.MED_HEADER_LENGTH_MASKED);
     private boolean tailClosed = false;
     private final ByteBuffer inputBuffer;
@@ -275,8 +280,13 @@ private boolean sendToUnderlyingInput() {
         private void processInput() throws TransportException {
             switch (webSocketState) {
                 case PN_WS_CONNECTING:
+                	inputBuffer.mark();
                     if (webSocketHandler.validateUpgradeReply(inputBuffer)) {
                         webSocketState = WebSocketState.PN_WS_CONNECTED_FLOW;
+                    } else {
+                    	// Input data was incomplete. Reset buffer position and wait for another call after more data arrives.
+                    	inputBuffer.reset();
+                    	TRACE_LOGGER.warn("Websocket connecting response incomplete");
                     }
                     inputBuffer.compact();
                     break;
diff --git a/src/test/java/com/microsoft/azure/proton/transport/ws/impl/WebSocketImplTest.java b/src/test/java/com/microsoft/azure/proton/transport/ws/impl/WebSocketImplTest.java
index ab9280d..3fb19b2 100644
--- a/src/test/java/com/microsoft/azure/proton/transport/ws/impl/WebSocketImplTest.java
+++ b/src/test/java/com/microsoft/azure/proton/transport/ws/impl/WebSocketImplTest.java
@@ -36,6 +36,8 @@
 import org.mockito.stubbing.Answer;
 
 import java.nio.ByteBuffer;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -422,6 +424,60 @@ public void testPending_state_flow_empty_output() {
         verify(mockWebSocketHandler, times(0)).wrapBuffer((ByteBuffer) any(), (ByteBuffer) any());
     }
 
+    @Test
+    public void testChunked_connection() {
+        init();
+
+        WebSocketHandlerImpl webSocketHandler = new WebSocketHandlerImpl();
+
+        WebSocketImpl webSocketImpl = new WebSocketImpl();
+        webSocketImpl.configure(_hostName, _webSocketPath, _webSocketQuery, _webSocketPort, _webSocketProtocol, _additionalHeaders, webSocketHandler);
+
+        TransportInput mockTransportInput = mock(TransportInput.class);
+        TransportOutput mockTransportOutput = mock(TransportOutput.class);
+        TransportWrapper transportWrapper = webSocketImpl.wrap(mockTransportInput, mockTransportOutput);
+
+        assertTrue(webSocketImpl.getState() == WebSocket.WebSocketState.PN_WS_NOT_STARTED);
+        transportWrapper.pending();
+        assertTrue(webSocketImpl.getState() == WebSocket.WebSocketState.PN_WS_CONNECTING);
+
+        // Get the key that the upgrade verifier will expect
+        String request = webSocketHandler.createUpgradeRequest("fakehost", "fakepath", "fakequery", 9999, "fakeprotocol", null);
+        String[] lines = request.split("\r\n");
+        String extractedKey = null;
+        for (String l : lines) {
+        	if (l.startsWith("Sec-WebSocket-Key: ")) {
+        		extractedKey = l.substring(19).trim();
+        		break;
+        	}
+        }
+        String expectedKey = null;
+        try {
+            MessageDigest messageDigest = MessageDigest.getInstance("SHA-1");
+            expectedKey = Base64.encodeBase64StringLocal(
+                    messageDigest.digest((extractedKey + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11").getBytes())).trim();
+        } catch (NoSuchAlgorithmException e) {
+            // can't happen since SHA-1 is a known digest
+        }
+        // Assemble a response that the upgrade verifier will accept
+        byte[] fakeInput = ("http/1.1 101 switching protocols\nupgrade websocket\nconnection upgrade\nsec-websocket-protocol fakeprotocol\nsec-websocket-accept " +
+        		expectedKey).getBytes();
+
+        // Feed the response to the verifier, adding one byte at a time to simulate a response broken into chunks.
+        // This test inspired by an issue with the IBM JRE which for some reason returned the service's response in multiple pieces.
+        int i = 0;
+        ByteBuffer inputBuffer = transportWrapper.tail();
+        for (i = 0; i < fakeInput.length - 1; i++) {
+            inputBuffer.put(fakeInput[i]);
+            transportWrapper.process();
+            assertTrue(webSocketImpl.getState() == WebSocket.WebSocketState.PN_WS_CONNECTING);
+        }
+        // Add the last byte and the state should change.
+        inputBuffer.put(fakeInput[i]);
+        transportWrapper.process();
+        assertTrue(webSocketImpl.getState() == WebSocket.WebSocketState.PN_WS_CONNECTED_FLOW);
+    }
+
     @Test
     public void testPending_state_flow_output_not_empty() {
         init();