1 files changed, 1 insertions, 1 deletions

diff --git a/src/CommandOutput.h b/src/CommandOutput.h
index 3763d625f..5682b4fd8 100644
--- a/src/CommandOutput.h
+++ b/src/CommandOutput.h
@@ -17,7 +17,7 @@ public:
 	virtual ~cCommandOutputCallback() {};  // Force a virtual destructor in subclasses
 	
 	/// Syntax sugar function, calls Out() with Printf()-ed parameters; appends a "\n"
-	void Out(const char * a_Fmt, ...);
+	void Out(const char * a_Fmt, ...) FORMATSTRING(2, 3);
 	
 	/// Called when the command wants to output anything; may be called multiple times
 	virtual void Out(const AString & a_Text) = 0;