diff --git a/library/bigdecimal/add_spec.rb b/library/bigdecimal/add_spec.rb
index 169a071aa..542713011 100644
--- a/library/bigdecimal/add_spec.rb
+++ b/library/bigdecimal/add_spec.rb
@@ -24,7 +24,7 @@
   end
 
   it "returns a + b with given precision" do
-    # documentation states, that precision ist optional, but it ain't,
+    # documentation states that precision is optional, but it ain't,
     @two.add(@one, 1).should == @three
     @one .add(@two, 1).should == @three
     @one.add(@one_minus, 1).should == @zero