2 files changed, 10 insertions, 1 deletions
diff --git a/activerecord/lib/active_record/attribute_assignment.rb b/activerecord/lib/active_record/attribute_assignment.rb
index a13bb9299a..75377bba57 100644
--- a/activerecord/lib/active_record/attribute_assignment.rb
+++ b/activerecord/lib/active_record/attribute_assignment.rb
@@ -45,7 +45,7 @@ module ActiveRecord
       if respond_to?("#{k}=")
         raise
       else
-        raise UnknownAttributeError, "unknown attribute: #{k}"
+        raise UnknownAttributeError.new(self, k)
       end
     end
 
diff --git a/activerecord/lib/active_record/errors.rb b/activerecord/lib/active_record/errors.rb
index cd31147414..017b8bace6 100644
--- a/activerecord/lib/active_record/errors.rb
+++ b/activerecord/lib/active_record/errors.rb
@@ -159,6 +159,15 @@ module ActiveRecord
 
   # Raised when unknown attributes are supplied via mass assignment.
   class UnknownAttributeError < NoMethodError
+
+    attr_reader :record, :attribute
+
+    def initialize(record, attribute)
+      @record = record
+      @attribute = attribute.to_s
+      super("unknown attribute: #{attribute}")
+    end
+
   end
 
   # Raised when an error occurred while doing a mass assignment to an attribute through the