Index: t/spec/S32-num/rat.t
===================================================================
--- t/spec/S32-num/rat.t	(revision 28165)
+++ t/spec/S32-num/rat.t	(working copy)
@@ -81,6 +81,10 @@
         is_approx($a / $b, $a.Num / $b.Num, "Rat / Rat works ($a, $b)");
         is_approx($b / $a, $b.Num / $a.Num, "Rat / Rat works ($a, $b)");
     }
+    
+    my $neg = -$a;
+    isa_ok($neg, Rat, "prefix<-> generates a Rat on $a");
+    is_approx($neg, -($a.Num), "prefix<-> generates the correct number for $a");
 }
 
 # SHOULD: Add divide by zero / zero denominator tests