diff --git a/src/ClientHandle.cpp b/src/ClientHandle.cpp
index 5ed5f1085..4513cfb38 100644
--- a/src/ClientHandle.cpp
+++ b/src/ClientHandle.cpp
@@ -2633,7 +2633,7 @@ void cClientHandle::PacketError(unsigned char a_PacketType)
 
 
 
-void cClientHandle::DataReceived(const char * a_Data, int a_Size)
+void cClientHandle::DataReceived(const char * a_Data, size_t a_Size)
 {
 	// Data is received from the client, store it in the buffer to be processed by the Tick thread:
 	m_TimeSinceLastPacket = 0;
diff --git a/src/ClientHandle.h b/src/ClientHandle.h
index 8366caa16..3fb653012 100644
--- a/src/ClientHandle.h
+++ b/src/ClientHandle.h
@@ -362,7 +362,7 @@ private:
 	void HandleCommandBlockMessage(const char * a_Data, unsigned int a_Length);
 	
 	// cSocketThreads::cCallback overrides:
-	virtual void DataReceived   (const char * a_Data, int a_Size) override;  // Data is received from the client
+	virtual void DataReceived   (const char * a_Data, size_t a_Size) override;  // Data is received from the client
 	virtual void GetOutgoingData(AString & a_Data) override;  // Data can be sent to client
 	virtual void SocketClosed   (void) override;  // The socket has been closed for any reason
 };										// tolua_export
diff --git a/src/HTTPServer/HTTPConnection.cpp b/src/HTTPServer/HTTPConnection.cpp
index 6d238f028..44a3d3f88 100644
--- a/src/HTTPServer/HTTPConnection.cpp
+++ b/src/HTTPServer/HTTPConnection.cpp
@@ -144,7 +144,7 @@ void cHTTPConnection::Terminate(void)
 
 
 
-void cHTTPConnection::DataReceived(const char * a_Data, int a_Size)
+void cHTTPConnection::DataReceived(const char * a_Data, size_t a_Size)
 {
 	switch (m_State)
 	{
@@ -181,9 +181,9 @@ void cHTTPConnection::DataReceived(const char * a_Data, int a_Size)
 			}
 			
 			// Process the rest of the incoming data into the request body:
-			if (a_Size > (int)BytesConsumed)
+			if (a_Size > BytesConsumed)
 			{
-				DataReceived(a_Data + BytesConsumed, a_Size - (int)BytesConsumed);
+				DataReceived(a_Data + BytesConsumed, a_Size - BytesConsumed);
 			}
 			else
 			{
diff --git a/src/HTTPServer/HTTPConnection.h b/src/HTTPServer/HTTPConnection.h
index 0ad409c51..fc11f1ba6 100644
--- a/src/HTTPServer/HTTPConnection.h
+++ b/src/HTTPServer/HTTPConnection.h
@@ -91,7 +91,7 @@ protected:
 	
 	
 	// cSocketThreads::cCallback overrides:
-	virtual void DataReceived   (const char * a_Data, int a_Size) override;  // Data is received from the client
+	virtual void DataReceived   (const char * a_Data, size_t a_Size) override;  // Data is received from the client
 	virtual void GetOutgoingData(AString & a_Data) override;  // Data can be sent to client
 	virtual void SocketClosed   (void) override;  // The socket has been closed for any reason
 } ;
diff --git a/src/HTTPServer/HTTPFormParser.cpp b/src/HTTPServer/HTTPFormParser.cpp
index 14d97bb7d..9ddfb82f1 100644
--- a/src/HTTPServer/HTTPFormParser.cpp
+++ b/src/HTTPServer/HTTPFormParser.cpp
@@ -52,7 +52,7 @@ cHTTPFormParser::cHTTPFormParser(cHTTPRequest & a_Request, cCallbacks & a_Callba
 
 
 
-cHTTPFormParser::cHTTPFormParser(eKind a_Kind, const char * a_Data, int a_Size, cCallbacks & a_Callbacks) :
+cHTTPFormParser::cHTTPFormParser(eKind a_Kind, const char * a_Data, size_t a_Size, cCallbacks & a_Callbacks) :
 	m_Callbacks(a_Callbacks),
 	m_Kind(a_Kind),
 	m_IsValid(true)
@@ -64,7 +64,7 @@ cHTTPFormParser::cHTTPFormParser(eKind a_Kind, const char * a_Data, int a_Size,
 
 
 
-void cHTTPFormParser::Parse(const char * a_Data, int a_Size)
+void cHTTPFormParser::Parse(const char * a_Data, size_t a_Size)
 {
 	if (!m_IsValid)
 	{
diff --git a/src/HTTPServer/HTTPFormParser.h b/src/HTTPServer/HTTPFormParser.h
index b8e6d246c..01d103bb8 100644
--- a/src/HTTPServer/HTTPFormParser.h
+++ b/src/HTTPServer/HTTPFormParser.h
@@ -36,6 +36,9 @@ public:
 	class cCallbacks
 	{
 	public:
+	
+		virtual ~cCallbacks() {};
+		
 		/// Called when a new file part is encountered in the form data
 		virtual void OnFileStart(cHTTPFormParser & a_Parser, const AString & a_FileName) = 0;
 		
@@ -51,10 +54,10 @@ public:
 	cHTTPFormParser(cHTTPRequest & a_Request, cCallbacks & a_Callbacks);
 	
 	/// Creates a parser with the specified content type that reads data from a string
-	cHTTPFormParser(eKind a_Kind, const char * a_Data, int a_Size, cCallbacks & a_Callbacks);
+	cHTTPFormParser(eKind a_Kind, const char * a_Data, size_t a_Size, cCallbacks & a_Callbacks);
 	
 	/// Adds more data into the parser, as the request body is received
-	void Parse(const char * a_Data, int a_Size);
+	void Parse(const char * a_Data, size_t a_Size);
 	
 	/** Notifies that there's no more data incoming and the parser should finish its parsing.
 	Returns true if parsing successful
diff --git a/src/HTTPServer/HTTPMessage.h b/src/HTTPServer/HTTPMessage.h
index c2d310839..dab942136 100644
--- a/src/HTTPServer/HTTPMessage.h
+++ b/src/HTTPServer/HTTPMessage.h
@@ -39,7 +39,7 @@ public:
 	void AddHeader(const AString & a_Key, const AString & a_Value);
 	
 	void SetContentType  (const AString & a_ContentType) { m_ContentType   = a_ContentType; }
-	void SetContentLength(int a_ContentLength)           { m_ContentLength = a_ContentLength; }
+	void SetContentLength(size_t a_ContentLength)        { m_ContentLength = a_ContentLength; }
 	
 	const AString & GetContentType  (void) const { return m_ContentType; }
 	size_t          GetContentLength(void) const { return m_ContentLength; }
diff --git a/src/OSSupport/SocketThreads.h b/src/OSSupport/SocketThreads.h
index b2eb5950f..679e374e1 100644
--- a/src/OSSupport/SocketThreads.h
+++ b/src/OSSupport/SocketThreads.h
@@ -64,7 +64,7 @@ public:
 		virtual ~cCallback() {}
 		
 		/** Called when data is received from the remote party */
-		virtual void DataReceived(const char * a_Data, int a_Size) = 0;
+		virtual void DataReceived(const char * a_Data, size_t a_Size) = 0;
 		
 		/** Called when data can be sent to remote party
 		The function is supposed to *set* outgoing data to a_Data (overwrite) */
diff --git a/src/RCONServer.cpp b/src/RCONServer.cpp
index 72f2d9ba9..d7083ff2b 100644
--- a/src/RCONServer.cpp
+++ b/src/RCONServer.cpp
@@ -169,7 +169,7 @@ cRCONServer::cConnection::cConnection(cRCONServer & a_RCONServer, cSocket & a_So
 
 
 
-void cRCONServer::cConnection::DataReceived(const char * a_Data, int a_Size)
+void cRCONServer::cConnection::DataReceived(const char * a_Data, size_t a_Size)
 {
 	// Append data to the buffer:
 	m_Buffer.append(a_Data, a_Size);
diff --git a/src/RCONServer.h b/src/RCONServer.h
index 88aac4b5f..b964852ab 100644
--- a/src/RCONServer.h
+++ b/src/RCONServer.h
@@ -65,7 +65,7 @@ protected:
 		
 
 		// cSocketThreads::cCallback overrides:
-		virtual void DataReceived(const char * a_Data, int a_Size) override;
+		virtual void DataReceived(const char * a_Data, size_t a_Size) override;
 		virtual void GetOutgoingData(AString & a_Data) override;
 		virtual void SocketClosed(void) override;