--- MultiPlay.cpp
+++ MultiPlay.cpp
@@ -42,7 +42,9 @@
 
 #else	/* ! WIN32 */
 
+#ifndef closesocket        /* see included ttincl.h */
 #define closesocket(FD) close(FD)
+#endif
 
 #endif
 
--- Network.cpp
+++ Network.cpp
@@ -41,7 +41,9 @@
 
 #else	/* ! WIN32 */
 
+#ifndef closesocket        /* see included ttincl.h */
 #define closesocket(FD) close(FD)
+#endif
 
 #endif