diff --git a/lib/validates_timeliness/validation_methods.rb b/lib/validates_timeliness/validation_methods.rb
index 18927aa..53c90e1 100644
--- a/lib/validates_timeliness/validation_methods.rb
+++ b/lib/validates_timeliness/validation_methods.rb
@@ -49,7 +49,7 @@ module ValidatesTimeliness
       private
 
       def validates_timeliness_of(attr_names, configuration)
-        validator = ValidatesTimeliness::Validator.new(configuration)
+        validator = ValidatesTimeliness::Validator.new(configuration.symbolize_keys)
         
         # bypass handling of allow_nil and allow_blank to validate raw value
         configuration.delete(:allow_nil)
diff --git a/lib/validates_timeliness/validator.rb b/lib/validates_timeliness/validator.rb
index 1e66d8d..8b2179f 100644
--- a/lib/validates_timeliness/validator.rb
+++ b/lib/validates_timeliness/validator.rb
@@ -19,12 +19,17 @@ module ValidatesTimeliness
       :between      => lambda {|v, r| (r.first..r.last).include?(v) } 
     }
 
+    VALID_OPTIONS = [
+      :on, :allow_nil, :empty, :allow_blank, :blank, :invalid_time_message, :invalid_date_message, :invalid_datetime_message
+    ] + RESTRICTION_METHODS.keys.map {|option| [option, "#{option}_message".to_sym] }.flatten
+
     attr_reader :configuration, :type
 
     def initialize(configuration)
       defaults = { :on => :save, :type => :datetime, :allow_nil => false, :allow_blank => false }
       @configuration = defaults.merge(configuration)
       @type = @configuration.delete(:type)
+      validate_options(@configuration)
     end
       
     def call(record, attr_name)
@@ -159,5 +164,12 @@ module ValidatesTimeliness
       end
     end
 
+    def validate_options(options)
+      invalid_types = [:time, :date, :datetime]
+      invalid_types.delete(@type)
+      valid_options = VALID_OPTIONS.reject {|option| invalid_types.include?("#{option}_message".to_sym) }
+      options.assert_valid_keys(valid_options)
+    end
+
   end
 end
diff --git a/spec/validator_spec.rb b/spec/validator_spec.rb
index bb73942..d5a2876 100644
--- a/spec/validator_spec.rb
+++ b/spec/validator_spec.rb
@@ -16,6 +16,23 @@ describe ValidatesTimeliness::Validator do
     @person = Person.new
   end
 
+  describe "option keys validation" do
+    before do
+      @valid_options = ValidatesTimeliness::Validator::VALID_OPTIONS.inject({}) {|hash, opt| hash[opt] = nil; hash } 
+      @valid_options.delete(:invalid_date_message)
+      @valid_options.delete(:invalid_time_message)
+    end
+
+    it "should raise error if invalid option key passed" do
+      @valid_options.update(:invalid_key => 'will not open lock')
+      lambda { Person.validates_datetime(@valid_options) }.should raise_error(ArgumentError)
+    end
+
+    it "should not raise error if option keys are valid" do
+      lambda { Person.validates_datetime(@valid_options) }.should_not raise_error(ArgumentError)
+    end
+  end
+
   describe "restriction_value" do
     it "should return Time object when restriction is Time object" do
       restriction_value(Time.now, :datetime).should be_kind_of(Time)