diff --git a/src/common/header/common.h b/src/common/header/common.h
index 62a39159..66c14ab5 100644
--- a/src/common/header/common.h
+++ b/src/common/header/common.h
@@ -739,7 +739,6 @@ void	Sys_SendKeyEvents (void);
 void	Sys_Error (char *error, ...);
 void	Sys_Quit (void);
 char	*Sys_GetClipboardData( void );
-void	Sys_CopyProtect (void);
 
 /* CLIENT / SERVER SYSTEMS */