Index: src/cmd/unit_physics.h
--- src/cmd/unit_physics.h.orig
+++ src/cmd/unit_physics.h
@@ -41,8 +41,6 @@
 #include "networking/lowlevel/vsnet_clientstate.h"
 #include "networking/netclient.h"
 
-extern float copysign( float x, float y );
-
 extern unsigned int apply_float_to_unsigned_int( float tmp ); //short fix
 
 template < class UnitType >
