@@ -74,10 +74,11 @@
 
 @interface OFHTTPClientRequestBodyStream: OFStream <OFReadyForWritingObserving>
 {
 	OFHTTPClientRequestHandler *_handler;
 	OFTCPSocket *_socket;
+	bool _chunked;
 	uintmax_t _toWrite;
 	bool _atEndOfStream;
 }
 
 - (instancetype)initWithHandler: (OFHTTPClientRequestHandler *)handler
@@ -548,10 +549,13 @@
       didWriteString: (OFString *)string
 	    encoding: (of_string_encoding_t)encoding
 	bytesWritten: (size_t)bytesWritten
 	   exception: (id)exception
 {
+	OFDictionary OF_GENERIC(OFString *, OFString *) *headers;
+	OFString *transferEncoding;
+
 	if (exception != nil) {
 		if ([exception isKindOfClass: [OFWriteFailedException class]] &&
 		    ([exception errNo] == ECONNRESET ||
 		    [exception errNo] == EPIPE)) {
 			/* In case a keep-alive connection timed out */
@@ -563,11 +567,15 @@
 		return nil;
 	}
 
 	_firstLine = true;
 
-	if ([_request.headers objectForKey: @"Content-Length"] != nil) {
+	headers = _request.headers;
+	transferEncoding = [headers objectForKey: @"Transfer-Encoding"];
+
+	if ([transferEncoding isEqual: @"chunked"] ||
+	    [headers objectForKey: @"Content-Length"] != nil) {
 		stream.delegate = nil;
 
 		OFStream *requestBody = [[[OFHTTPClientRequestBodyStream alloc]
 		    initWithHandler: self
 			     socket: (OFTCPSocket *)stream] autorelease];
@@ -702,28 +710,32 @@
 	self = [super init];
 
 	@try {
 		OFDictionary OF_GENERIC(OFString *, OFString *) *headers;
 		intmax_t contentLength;
-		OFString *contentLengthString;
+		OFString *transferEncoding, *contentLengthString;
 
 		_handler = [handler retain];
 		_socket = [sock retain];
 
 		headers = _handler->_request.headers;
+
+		transferEncoding = [headers objectForKey: @"Transfer-Encoding"];
+		_chunked = [transferEncoding isEqual: @"chunked"];
 
 		contentLengthString = [headers objectForKey: @"Content-Length"];
-		if (contentLengthString == nil)
-			@throw [OFInvalidArgumentException exception];
-
-		contentLength = contentLengthString.decimalValue;
-		if (contentLength < 0)
-			@throw [OFOutOfRangeException exception];
-
-		_toWrite = contentLength;
-
-		if ([headers objectForKey: @"Transfer-Encoding"] != nil)
+		if (contentLengthString != nil) {
+			if (_chunked)
+				@throw [OFInvalidArgumentException
+				    exception];
+
+			contentLength = contentLengthString.decimalValue;
+			if (contentLength < 0)
+				@throw [OFOutOfRangeException exception];
+
+			_toWrite = contentLength;
+		} else if (!_chunked)
 			@throw [OFInvalidArgumentException exception];
 	} @catch (id e) {
 		[self release];
 		@throw e;
 	}
@@ -748,30 +760,42 @@
 	size_t ret;
 
 	if (_socket == nil)
 		@throw [OFNotOpenException exceptionWithObject: self];
 
+	/*
+	 * We must not send a chunk of size 0, as that would end the body. We
+	 * always ignore writing 0 bytes to still allow writing 0 bytes after
+	 * the end of stream.
+	 */
+	if (length == 0)
+		return 0;
+
 	if (_atEndOfStream)
 		@throw [OFWriteFailedException
 		    exceptionWithObject: self
 			requestedLength: requestedLength
 			   bytesWritten: 0
 				  errNo: 0];
 
-	if (length > _toWrite)
+	if (_chunked)
+		[_socket writeFormat: @"%zX\r\n", length];
+	else if (length > _toWrite)
 		length = (size_t)_toWrite;
 
 	ret = [_socket writeBuffer: buffer
 			    length: length];
 
 	if (ret > length)
 		@throw [OFOutOfRangeException exception];
 
-	_toWrite -= ret;
+	if (!_chunked) {
+		_toWrite -= ret;
 
-	if (_toWrite == 0)
-		_atEndOfStream = true;
+		if (_toWrite == 0)
+			_atEndOfStream = true;
+	}
 
 	if (requestedLength > length)
 		@throw [OFWriteFailedException
 		    exceptionWithObject: self
 			requestedLength: requestedLength
@@ -789,11 +813,13 @@
 - (void)close
 {
 	if (_socket == nil)
 		@throw [OFNotOpenException exceptionWithObject: self];
 
-	if (_toWrite > 0)
+	if (_chunked)
+		[_socket writeString: @"0\r\n"];
+	else if (_toWrite > 0)
 		@throw [OFTruncatedDataException exception];
 
 	_socket.delegate = _handler;
 	[_socket asyncReadLine];
 
@@ -838,10 +864,13 @@
 	_chunked = [[headers objectForKey: @"Transfer-Encoding"]
 	    isEqual: @"chunked"];
 
 	contentLength = [headers objectForKey: @"Content-Length"];
 	if (contentLength != nil) {
+		if (_chunked)
+			@throw [OFInvalidServerReplyException exception];
+
 		_hasContentLength = true;
 
 		@try {
 			intmax_t toRead = contentLength.decimalValue;