diff -urNad vdr-1.3.34~/svdrp.h vdr-1.3.34/svdrp.h
--- vdr-1.3.34~/svdrp.h	2005-10-05 19:47:23.779606359 +0100
+++ vdr-1.3.34/svdrp.h	2005-10-05 19:52:16.879173995 +0100
@@ -51,7 +51,7 @@
   time_t lastActivity;
   void Close(bool Timeout = false);
   bool Send(const char *s, int length = -1);
-  void Reply(int Code, const char *fmt, ...);
+  void Reply(int Code, const char *fmt, ...) __attribute__ ((format (printf, 3, 4)));
   void PrintHelpTopics(const char **hp);
   void CmdCHAN(const char *Option);
   void CmdCLRE(const char *Option);
diff -urNad vdr-1.3.34~/thread.h vdr-1.3.34/thread.h
--- vdr-1.3.34~/thread.h	2005-08-14 12:21:48.000000000 +0100
+++ vdr-1.3.34/thread.h	2005-10-05 19:50:39.421967868 +0100
@@ -106,7 +106,7 @@
        ///< the thread starts and stops. The Start() function must be called 
        ///< to actually start the thread.
   virtual ~cThread();
-  void SetDescription(const char *Description, ...);
+  void SetDescription(const char *Description, ...) __attribute__ ((format (printf, 2, 3)));
   bool Start(void);
        ///< Actually starts the thread.
   bool Active(void);
diff -urNad vdr-1.3.34~/tools.h vdr-1.3.34/tools.h
--- vdr-1.3.34~/tools.h	2005-10-01 13:43:31.000000000 +0100
+++ vdr-1.3.34/tools.h	2005-10-05 19:51:24.438829682 +0100
@@ -81,7 +81,7 @@
   operator const char * () const { return s; } // for use in (const char *) context
   const char * operator*() const { return s; } // for use in (const void *) context (printf() etc.)
   cString &operator=(const cString &String);
-  static cString sprintf(const char *fmt, ...);
+  static cString sprintf(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
   };
 
 ssize_t safe_read(int filedes, void *buffer, size_t size);