diff --git a/lib/validates_timeliness/validator.rb b/lib/validates_timeliness/validator.rb
index 1c1c0d0..16bd42d 100644
--- a/lib/validates_timeliness/validator.rb
+++ b/lib/validates_timeliness/validator.rb
@@ -60,6 +60,7 @@ module ValidatesTimeliness
     def validate_restrictions(record, attr_name, value)
       if configuration[:with_time] || configuration[:with_date]
         value = combine_date_and_time(value, record)
+        return if value.nil?
       end
 
       value = self.class.type_cast_value(value, implied_type, configuration[:ignore_usec])
diff --git a/spec/validator_spec.rb b/spec/validator_spec.rb
index 657228b..b9826fa 100644
--- a/spec/validator_spec.rb
+++ b/spec/validator_spec.rb
@@ -442,6 +442,12 @@ describe ValidatesTimeliness::Validator do
       should_have_no_error(:birth_date, :on_or_before)
     end
 
+    it "should skip restriction validation if :with_time value evaluates to nil" do
+      configure_validator(:type => :date, :with_time => lambda { nil }, :on_or_before => Time.mktime(2000,1,1,12,30))
+      validate_with(:birth_date, "2000-01-01")
+      should_have_no_error(:birth_date, :on_or_before)
+    end
+
     it "should should ignore usec value on combined value if :ignore_usec option is true" do
       configure_validator(:type => :date, :with_time => Time.mktime(2000,1,1,12,30,0,500), :is_at => Time.mktime(2000,1,1,12,30), :ignore_usec => true)
       validate_with(:birth_date, "2000-01-01")
@@ -463,6 +469,12 @@ describe ValidatesTimeliness::Validator do
       should_have_no_error(:birth_time, :on_or_before)
     end
 
+    it "should skip restriction validation if :with_date value is nil" do
+      configure_validator(:type => :time, :with_date => lambda { nil }, :on_or_before => Time.mktime(2000,1,1,12,30))
+      validate_with(:birth_time, "12:30")
+      should_have_no_error(:birth_time, :on_or_before)
+    end
+
     it "should should ignore usec value on combined value if :ignore_usec option is true" do
       configure_validator(:type => :time, :with_date => Date.new(2000,1,1), :on_or_before => Time.mktime(2000,1,1,12,30), :ignore_usec => true)
       validate_with(:birth_time, Time.mktime(2000,1,1,12,30,0,50))