diff --git a/lib/schema/schema/compare/comparison.rb b/lib/schema/schema/compare/comparison.rb
index <HASH>..<HASH> 100644
--- a/lib/schema/schema/compare/comparison.rb
+++ b/lib/schema/schema/compare/comparison.rb
@@ -28,11 +28,11 @@ module Schema
 
       def self.assure_schemas(control, compare)
         if not control.is_a?(Schema)
-          raise Error, 'Control object is not an implementation of Schema'
+          raise Error, 'Control object is not an implementation of Schema (Control Class: #{control.class.name})'
         end
 
         if not compare.is_a?(Schema)
-          raise Error, 'Compare object is not an implementation of Schema'
+          raise Error, 'Compare object is not an implementation of Schema (Compare Class: #{compare.class.name})'
         end
       end
Control and compare classes are printed in the error message when inputs aren't Schema instances