diff --git a/README.md b/README.md
index b1c7fda..3a9019c 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@ Use of the library requires Java 8 or higher and can be done via one of the foll
 <dependency>
   <groupId>net.interfax</groupId>
   <artifactId>api-client</artifactId>
-  <version>0.12</version>
+  <version>0.14</version>
 </dependency>
 ```
     
diff --git a/src/main/java/net/interfax/rest/client/impl/DefaultInterFAXClient.java b/src/main/java/net/interfax/rest/client/impl/DefaultInterFAXClient.java
index 703ac34..f40152f 100644
--- a/src/main/java/net/interfax/rest/client/impl/DefaultInterFAXClient.java
+++ b/src/main/java/net/interfax/rest/client/impl/DefaultInterFAXClient.java
@@ -163,7 +163,7 @@ public APIResponse sendFax(final String faxNumber, final String urlOfDoc, final
         URI uri = getSendFaxUri(faxNumber, options);
         return executePostRequest(
                 uri,
-                target -> target.request().header("Content-Location", urlOfDoc).header("Content-Length", 0).post(null)
+                target -> target.request().header("Content-Location", urlOfDoc).header("Content-Length", 0).post(Entity.entity(new byte[0], MediaType.APPLICATION_OCTET_STREAM_TYPE))
         );
     }
 
@@ -323,7 +323,7 @@ public APIResponse uploadDocument(final File fileToUpload, final Optional<Docume
             URI outboundDocumentsUri = getOutboundDocumentsUri(fileToUpload, options);
 
             WebTarget target = client.target(outboundDocumentsUri);
-            response = target.request().header("Content-Length", 0).post(null);
+            response = target.request().header("Content-Length", 0).post(Entity.entity(new byte[0], MediaType.APPLICATION_OCTET_STREAM_TYPE));
 
             apiResponse = new APIResponse();
             apiResponse.setStatusCode(response.getStatus());
@@ -390,11 +390,14 @@ public APIResponse uploadChunk(String uploadChunkToDocumentEndpoint,
                     .header("Range", "bytes="+startByteRange+"-"+endByteRange)
                     .post(Entity.entity(bytesToUpload, MediaType.APPLICATION_OCTET_STREAM_TYPE));
 
-            int expectedResponseCode = lastChunk ?
-                                        Response.Status.OK.getStatusCode():
-                                        Response.Status.ACCEPTED.getStatusCode();
 
-            if (response.getStatus() == expectedResponseCode) {
+            final int OK = Response.Status.OK.getStatusCode();
+            final int ACCEPTED = Response.Status.ACCEPTED.getStatusCode();
+            final int NO_CONTENT = Response.Status.NO_CONTENT.getStatusCode(); // 204: No content
+
+
+            if ((lastChunk && response.getStatus() == OK) ||
+                (!lastChunk && (response.getStatus() == ACCEPTED || response.getStatus() == NO_CONTENT))) {
                 log.info(
                         "chunk uploaded at {}; totalByesUploaded = {}; lastChunk = {}",
                         uploadChunkToDocumentEndpoint,
@@ -711,4 +714,4 @@ private void initializeClient(String username, String password) {
             reentrantLock.unlock();
         }
     }
-}
\ No newline at end of file
+}