diff --git a/lib/rackstash/buffer.rb b/lib/rackstash/buffer.rb
index 518ce7d..aa5644c 100644
--- a/lib/rackstash/buffer.rb
+++ b/lib/rackstash/buffer.rb
@@ -217,7 +217,7 @@ module Rackstash
     def timestamp(time = nil)
       @timestamp ||= begin
         time ||= Time.now
-        time.utc.iso8601(ISO8601_PRECISION).freeze
+        time.getutc.iso8601(ISO8601_PRECISION).freeze
       end
     end
   end
diff --git a/lib/rackstash/fields/abstract_collection.rb b/lib/rackstash/fields/abstract_collection.rb
index 7a8068e..5dfa130 100644
--- a/lib/rackstash/fields/abstract_collection.rb
+++ b/lib/rackstash/fields/abstract_collection.rb
@@ -149,7 +149,7 @@ module Rackstash
           end
           return array
         when ::Time
-          return value.utc.iso8601(ISO8601_PRECISION).freeze
+          return value.getutc.iso8601(ISO8601_PRECISION).freeze
         when ::DateTime
           return value.to_time.utc.iso8601(ISO8601_PRECISION).freeze
         when ::Date
diff --git a/spec/rackstash/buffer_spec.rb b/spec/rackstash/buffer_spec.rb
index 4be0f1c..f92c3aa 100644
--- a/spec/rackstash/buffer_spec.rb
+++ b/spec/rackstash/buffer_spec.rb
@@ -304,7 +304,7 @@ describe Rackstash::Buffer do
       now = Time.parse('2016-10-17 13:37:00 +03:00')
 
       expect(Time).to receive(:now).once.and_return(now)
-      expect(now).to receive(:utc).once.and_return(now.utc)
+      expect(now).to receive(:getutc).once.and_return(now.getutc)
 
       expect(buffer.timestamp).to eql '2016-10-17T10:37:00.000Z'
       expect(buffer.timestamp).to eql '2016-10-17T10:37:00.000Z'