diff --git a/lib/fog/aws/requests/sts/get_federation_token.rb b/lib/fog/aws/requests/sts/get_federation_token.rb
index 84e96e8e6..d56df8bdc 100644
--- a/lib/fog/aws/requests/sts/get_federation_token.rb
+++ b/lib/fog/aws/requests/sts/get_federation_token.rb
@@ -11,6 +11,7 @@ module Fog
             'Name'            => name,
             'Policy'          => MultiJson.encode(policy),
             'DurationSeconds' => duration,
+            :idempotent       => true,
             :parser           => Fog::Parsers::AWS::STS::GetSessionToken.new
           })
         end
diff --git a/lib/fog/aws/requests/sts/get_session_token.rb b/lib/fog/aws/requests/sts/get_session_token.rb
index b188a22cc..f76531ba4 100644
--- a/lib/fog/aws/requests/sts/get_session_token.rb
+++ b/lib/fog/aws/requests/sts/get_session_token.rb
@@ -9,6 +9,7 @@ module Fog
           request({
             'Action'          => 'GetSessionToken',
             'DurationSeconds' => duration,
+            :idempotent       => true,
             :parser           => Fog::Parsers::AWS::STS::GetSessionToken.new
           })
         end