diff --git a/headers/os/net/DatagramSocket.h b/headers/os/net/DatagramSocket.h
index c4c2a2033b..c555a9105d 100644
--- a/headers/os/net/DatagramSocket.h
+++ b/headers/os/net/DatagramSocket.h
@@ -26,9 +26,9 @@ public:
 
 	virtual	size_t				MaxTransmissionSize() const;
 
-	virtual	size_t				SendTo(const BNetworkAddress& address,
+	virtual	ssize_t				SendTo(const BNetworkAddress& address,
 									const void* buffer, size_t size);
-	virtual	size_t				ReceiveFrom(void* buffer, size_t bufferSize,
+	virtual	ssize_t				ReceiveFrom(void* buffer, size_t bufferSize,
 									BNetworkAddress& from);
 
 	// BDataIO implementation
diff --git a/src/kits/network/libnetapi/DatagramSocket.cpp b/src/kits/network/libnetapi/DatagramSocket.cpp
index 15be2fac86..23f59ab06c 100644
--- a/src/kits/network/libnetapi/DatagramSocket.cpp
+++ b/src/kits/network/libnetapi/DatagramSocket.cpp
@@ -79,7 +79,7 @@ BDatagramSocket::MaxTransmissionSize() const
 }
 
 
-size_t
+ssize_t
 BDatagramSocket::SendTo(const BNetworkAddress& address, const void* buffer,
 	size_t size)
 {
@@ -92,7 +92,7 @@ BDatagramSocket::SendTo(const BNetworkAddress& address, const void* buffer,
 }
 
 
-size_t
+ssize_t
 BDatagramSocket::ReceiveFrom(void* buffer, size_t bufferSize,
 	BNetworkAddress& from)
 {