diff --git a/apis/s3/pom.xml b/apis/s3/pom.xml
index 364e233..17de087 100644
--- a/apis/s3/pom.xml
+++ b/apis/s3/pom.xml
@@ -87,6 +87,11 @@
       <artifactId>log4j</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.google.mockwebserver</groupId>
+      <artifactId>mockwebserver</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <profiles>
diff --git a/apis/s3/src/test/java/org/jclouds/s3/S3ClientMockTest.java b/apis/s3/src/test/java/org/jclouds/s3/S3ClientMockTest.java
new file mode 100644
index 0000000..6931d49
--- /dev/null
+++ b/apis/s3/src/test/java/org/jclouds/s3/S3ClientMockTest.java
@@ -0,0 +1,84 @@
+/**
+ * Licensed to jclouds, Inc. (jclouds) under one or more
+ * contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  jclouds 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.
+ */
+package org.jclouds.s3;
+
+import static com.google.common.net.HttpHeaders.CONTENT_LENGTH;
+import static com.google.common.net.HttpHeaders.ETAG;
+import static com.google.common.util.concurrent.MoreExecutors.sameThreadExecutor;
+import static org.jclouds.s3.reference.S3Constants.PROPERTY_S3_VIRTUAL_HOST_BUCKETS;
+import static org.testng.Assert.assertEquals;
+
+import java.io.IOException;
+import java.net.URL;
+import java.util.Properties;
+import java.util.Set;
+
+import org.jclouds.ContextBuilder;
+import org.jclouds.concurrent.config.ExecutorServiceModule;
+import org.jclouds.rest.RestContext;
+import org.jclouds.s3.domain.S3Object;
+import org.testng.annotations.Test;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.google.inject.Module;
+import com.google.mockwebserver.MockResponse;
+import com.google.mockwebserver.MockWebServer;
+import com.google.mockwebserver.RecordedRequest;
+
+/**
+ * 
+ * @author Adrian Cole
+ */
+@Test
+public class S3ClientMockTest {
+
+   private static final Set<Module> modules = ImmutableSet.<Module> of(
+         new ExecutorServiceModule(sameThreadExecutor(), sameThreadExecutor()));
+
+   static RestContext<? extends S3Client,? extends  S3AsyncClient> getContext(URL server) {
+      Properties overrides = new Properties();
+      overrides.setProperty(PROPERTY_S3_VIRTUAL_HOST_BUCKETS, "false");
+
+      return ContextBuilder.newBuilder("s3")
+                           .credentials("accessKey", "secretKey")
+                           .endpoint(server.toString())
+                           .modules(modules)
+                           .overrides(overrides)
+                           .build(S3ApiMetadata.CONTEXT_TOKEN);
+   }
+
+   public void testZeroLengthPutHasContentLengthHeader() throws IOException, InterruptedException {
+      MockWebServer server = new MockWebServer();
+      server.enqueue(new MockResponse().setBody("").addHeader(ETAG, "ABCDEF"));
+      server.play();
+
+      S3Client client = getContext(server.getUrl("/")).getApi();
+      S3Object nada = client.newS3Object();
+      nada.getMetadata().setKey("object");
+      nada.setPayload(new byte[] {});
+      
+      assertEquals(client.putObject("bucket", nada), "ABCDEF");
+
+      RecordedRequest request = server.takeRequest();
+      assertEquals(request.getRequestLine(), "PUT /bucket/object HTTP/1.1");
+      assertEquals(request.getHeaders(CONTENT_LENGTH), ImmutableList.of("0"));
+      server.shutdown();
+   }
+}
diff --git a/core/src/main/java/org/jclouds/http/internal/JavaUrlHttpCommandExecutorService.java b/core/src/main/java/org/jclouds/http/internal/JavaUrlHttpCommandExecutorService.java
index 21d4c9b..0816e20 100644
--- a/core/src/main/java/org/jclouds/http/internal/JavaUrlHttpCommandExecutorService.java
+++ b/core/src/main/java/org/jclouds/http/internal/JavaUrlHttpCommandExecutorService.java
@@ -214,27 +214,33 @@
             // http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6755625
             checkArgument(length < Integer.MAX_VALUE,
                   "JDK 1.6 does not support >2GB chunks. Use chunked encoding, if possible.");
-            connection.setRequestProperty(CONTENT_LENGTH, length + "");
             if (length > 0) {
                writePayloadToConnection(payload, connection);
+            } else {
+               writeNothing(connection);
             }
          }
       } else {
-         connection.setRequestProperty(CONTENT_LENGTH, "0");
-         // for some reason POST/PUT undoes the content length header above.
-         if (ImmutableSet.of("POST", "PUT").contains(connection.getRequestMethod())) {
-            connection.setFixedLengthStreamingMode(0);
-            connection.setDoOutput(true);
-         }
+         writeNothing(connection);
       }
       return connection;
    }
 
+   protected void writeNothing(HttpURLConnection connection) {
+      connection.setRequestProperty(CONTENT_LENGTH, "0");
+      // for some reason POST/PUT undoes the content length header above.
+      if (ImmutableSet.of("POST", "PUT").contains(connection.getRequestMethod())) {
+         connection.setFixedLengthStreamingMode(0);
+         connection.setDoOutput(true);
+      }
+   }
+
    void writePayloadToConnection(Payload payload, HttpURLConnection connection) throws IOException {
       Long length = payload.getContentMetadata().getContentLength();
+      connection.setRequestProperty(CONTENT_LENGTH, length.toString());
+      connection.setRequestProperty("Expect", "100-continue");
       connection.setFixedLengthStreamingMode(length.intValue());
       connection.setDoOutput(true);
-      connection.setRequestProperty("Expect", "100-continue");
       CountingOutputStream out = new CountingOutputStream(connection.getOutputStream());
       try {
          payload.writeTo(out);
diff --git a/project/pom.xml b/project/pom.xml
index 6aaf69f..cfe83a5 100644
--- a/project/pom.xml
+++ b/project/pom.xml
@@ -271,6 +271,11 @@
                 <artifactId>logback-core</artifactId>
                 <version>1.0.7</version>
             </dependency>
+            <dependency>
+                <groupId>com.google.mockwebserver</groupId>
+                <artifactId>mockwebserver</artifactId>
+                <version>20121111</version>
+            </dependency>
         </dependencies>
     </dependencyManagement>
     <dependencies>