--- src/network/net_udp.cpp
+++ src/network/net_udp.cpp
@@ -178,7 +178,7 @@
     struct hostent *local;
     char	buff[MAXHOSTNAMELEN]="\0";
     struct sockaddr addr;
-    char *colon;
+    const char *colon;
 
 #ifdef WIN32
     WSADATA		winsockdata;
@@ -232,9 +232,9 @@
 
     ANET_GetSocketAddr (net_controlsocket, &addr);
     my_tcpip_address=ANET_AddrToString (&addr);
-    colon = strrchr (my_tcpip_address, ':');
+    colon = (strrchr (my_tcpip_address, ':'));
     if (colon)
-        *colon = 0;
+        *const_cast<char*>(colon) = 0;
 
     //  Con_Printf("UDP Initialized\n");
     tcpipAvailable = true;