diff --git a/core/time/minus_spec.rb b/core/time/minus_spec.rb
index 8449778465..9182d99652 100644
--- a/core/time/minus_spec.rb
+++ b/core/time/minus_spec.rb
@@ -109,7 +109,7 @@
 
   it "does not return a subclass instance" do
     c = Class.new(Time)
-    x = c.now + 1
+    x = c.now - 1
     x.should be_an_instance_of(Time)
   end