diff --git a/lib/ex_aws/kinesis.ex b/lib/ex_aws/kinesis.ex
index aa21b99..51e2ed8 100644
--- a/lib/ex_aws/kinesis.ex
+++ b/lib/ex_aws/kinesis.ex
@@ -57,6 +57,22 @@ defmodule ExAws.Kinesis do
     request(:delete_stream, %{"StreamName" => stream_name})
   end
 
+  @doc "  
+    You can increase the retention period up to a maximum of 8760 hours (365 days)
+    or decrease the retention period down to a minimum of 24 hours
+  "
+  @type retention_period_opts ::
+    :increase_stream_retention_period |
+    :decrease_stream_retention_period
+    @spec update_retention_period(stream_name :: stream_name, retention_period_hours :: pos_integer, action :: retention_period_opts) :: ExAws.Operation.JSON.t
+  def update_retention_period(stream_name, retention_period_hours, action) do
+    data = %{
+      "StreamName" => stream_name,
+      "RetentionPeriodHours" => retention_period_hours
+    }
+    request(action, data)
+  end     
+
   ## Records
   ######################