diff --git a/lib/tzinfo/timezone_transition_definition.rb b/lib/tzinfo/timezone_transition_definition.rb
index 26c7da86..263d1951 100644
--- a/lib/tzinfo/timezone_transition_definition.rb
+++ b/lib/tzinfo/timezone_transition_definition.rb
@@ -97,5 +97,10 @@ def eql?(tti)
     def hash
       @offset.hash ^ @previous_offset.hash ^ @numerator_or_time.hash ^ @denominator.hash
     end
+
+    def freeze
+      at # to fully initialize object before freeze
+      super
+    end
   end
 end
diff --git a/test/tc_timezone_transition_definition.rb b/test/tc_timezone_transition_definition.rb
index a542c129..82585fff 100644
--- a/test/tc_timezone_transition_definition.rb
+++ b/test/tc_timezone_transition_definition.rb
@@ -281,4 +281,12 @@ def test_hash
         t6.hash)
     end
   end
+
+  def test_freeze_when_not_fully_initialized
+    transition = TimezoneTransitionDefinition.new(TimezoneOffset.new(3600, 3600, :TDT),
+                                        TimezoneOffset.new(3600, 0, :TST), 1148949080)
+    transition.freeze
+
+    assert_nothing_raised { transition.at }
+  end
 end