Index: Language.php
===================================================================
--- Language.php	(revision 18457)
+++ Language.php	(working copy)
@@ -1163,7 +1163,10 @@
 			if (!is_null($s)) { $number = strtr($number, $s); }
 		}
 
-		return $number;
+		# Some people got upset about computers using - instead of −
+		return $number < 0
+				? '&minus;' . (string)abs( $number )
+				: $number;
 	}
 
 	/**