--- a/src/signs.h	Thu Aug 30 19:20:15 2007 +0000
+++ b/src/signs.h	Thu Aug 30 20:40:33 2007 +0000
@@ -26,7 +26,7 @@
 	/** Destroy the sign */
 	~Sign();
 
-	bool IsValid() const { return this->str != STR_NULL; }
+	inline bool IsValid() const { return this->str != STR_NULL; }
 };
 
 enum {