diff --git a/httpclient/src/main/java/org/apache/http/impl/client/AbstractHttpClient.java b/httpclient/src/main/java/org/apache/http/impl/client/AbstractHttpClient.java
index 7480c842d..332140519 100644
--- a/httpclient/src/main/java/org/apache/http/impl/client/AbstractHttpClient.java
+++ b/httpclient/src/main/java/org/apache/http/impl/client/AbstractHttpClient.java
@@ -625,15 +625,41 @@ public abstract class AbstractHttpClient implements HttpClient {
         return execute(determineTarget(request), request, context);
     }
 
-    private HttpHost determineTarget(HttpUriRequest request) throws ClientProtocolException {
+    // Package-protected so can be accessed from unit tests
+    static HttpHost determineTarget(HttpUriRequest request) throws ClientProtocolException {
         // A null target may be acceptable if there is a default target.
         // Otherwise, the null target is detected in the director.
         HttpHost target = null;
 
         URI requestURI = request.getURI();
         if (requestURI.isAbsolute()) {
+            int port = requestURI.getPort(); // may be overridden later
             String host = requestURI.getHost();
-            int port = requestURI.getPort();
+            if (host == null) { // normal parse failed; let's do it ourselves
+                // authority does not seem to care about the valid character-set for host names
+                host = requestURI.getAuthority();
+                if (host != null) {
+                    // Strip off any leading user credentials
+                    int at = host.indexOf('@');
+                    if (at >= 0) {
+                        if (host.length() > at+1 ) {
+                            host = host.substring(at+1);
+                        } else {
+                            host = null; // @ on its own
+                        }
+                    }
+                    // Extract the port suffix, if present
+                    if (host != null) { 
+                        int colon = host.indexOf(':');
+                        if (colon >= 0) {
+                            if (colon+1 < host.length()) {
+                                port = Integer.parseInt(host.substring(colon+1));
+                            }
+                            host = host.substring(0,colon);
+                        }                
+                    }                    
+                }
+            }
             String scheme = requestURI.getScheme();
             if (host == null) {
                 throw new ClientProtocolException(
diff --git a/httpclient/src/test/java/org/apache/http/impl/client/TestAbstractHttpClient.java b/httpclient/src/test/java/org/apache/http/impl/client/TestAbstractHttpClient.java
new file mode 100644
index 000000000..b70b145d4
--- /dev/null
+++ b/httpclient/src/test/java/org/apache/http/impl/client/TestAbstractHttpClient.java
@@ -0,0 +1,63 @@
+/*
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+
+package org.apache.http.impl.client;
+
+import static org.junit.Assert.assertEquals;
+
+import org.apache.http.HttpHost;
+import org.apache.http.client.methods.HttpHead;
+import org.junit.Test;
+
+/**
+ * Unit tests for {@link AbstractHttpClient}.
+ */
+public class TestAbstractHttpClient {
+
+    @Test
+    public void testHTTPCLIENT_911() throws Exception{
+        assertEquals(new HttpHost("localhost"),AbstractHttpClient.determineTarget(new HttpHead("http://localhost/abcd")));
+        assertEquals(new HttpHost("localhost"),AbstractHttpClient.determineTarget(new HttpHead("http://localhost/abcd%3A")));
+        
+        assertEquals(new HttpHost("local_host"),AbstractHttpClient.determineTarget(new HttpHead("http://local_host/abcd")));
+        assertEquals(new HttpHost("local_host"),AbstractHttpClient.determineTarget(new HttpHead("http://local_host/abcd%3A")));
+        
+        assertEquals(new HttpHost("localhost",8),AbstractHttpClient.determineTarget(new HttpHead("http://localhost:8/abcd")));
+        assertEquals(new HttpHost("local_host",8),AbstractHttpClient.determineTarget(new HttpHead("http://local_host:8/abcd")));
+
+        // URI seems to OK with missing port number
+        assertEquals(new HttpHost("localhost"),AbstractHttpClient.determineTarget(new HttpHead("http://localhost:/abcd")));
+        assertEquals(new HttpHost("local_host"),AbstractHttpClient.determineTarget(new HttpHead("http://local_host:/abcd")));
+
+        assertEquals(new HttpHost("localhost",8080),AbstractHttpClient.determineTarget(new HttpHead("http://user:pass@localhost:8080/abcd")));
+        assertEquals(new HttpHost("local_host",8080),AbstractHttpClient.determineTarget(new HttpHead("http://user:pass@local_host:8080/abcd")));
+
+        assertEquals(new HttpHost("localhost",8080),AbstractHttpClient.determineTarget(new HttpHead("http://@localhost:8080/abcd")));
+        assertEquals(new HttpHost("local_host",8080),AbstractHttpClient.determineTarget(new HttpHead("http://@local_host:8080/abcd")));
+
+    }
+}