diff --git a/CHANGELOG.md b/CHANGELOG.md
index b9f86782..c4d9627d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,8 +14,13 @@ The format is based on [Keep a Changelog], and this project adheres to
 
 - Test on Ruby 3.0 and 3.1 in the CI build ([#366]).
 
+### Changed
+
+- Pass an options hash to the AWS SDK, instead of keyword arguments ([#371]).
+
 [Unreleased]: https://github.com/envato/stack_master/compare/v2.13.2...HEAD
 [#366]: https://github.com/envato/stack_master/pull/366
+[#371]: https://github.com/envato/stack_master/pull/371
 
 ## [2.13.2] - 2022-01-25
 
diff --git a/features/step_definitions/asume_role_steps.rb b/features/step_definitions/asume_role_steps.rb
index 343b0fcc..0e64f44c 100644
--- a/features/step_definitions/asume_role_steps.rb
+++ b/features/step_definitions/asume_role_steps.rb
@@ -1,7 +1,7 @@
 Then(/^I expect the role "([^"]*)" is assumed in account "([^"]*)"$/) do |role, account|
-  expect(Aws::AssumeRoleCredentials).to receive(:new).with(
+  expect(Aws::AssumeRoleCredentials).to receive(:new).with({
     region: instance_of(String),
     role_arn: "arn:aws:iam::#{account}:role/#{role}",
     role_session_name: instance_of(String)
-  )
+  })
 end
diff --git a/lib/stack_master/aws_driver/cloud_formation.rb b/lib/stack_master/aws_driver/cloud_formation.rb
index 164f2bca..314d3927 100644
--- a/lib/stack_master/aws_driver/cloud_formation.rb
+++ b/lib/stack_master/aws_driver/cloud_formation.rb
@@ -36,7 +36,7 @@ def set_region(value)
       private
 
       def cf
-        @cf ||= Aws::CloudFormation::Client.new(region: region, retry_limit: 10)
+        @cf ||= Aws::CloudFormation::Client.new({ region: region, retry_limit: 10 })
       end
 
     end
diff --git a/lib/stack_master/aws_driver/s3.rb b/lib/stack_master/aws_driver/s3.rb
index 2cce498b..a8f7c1dc 100644
--- a/lib/stack_master/aws_driver/s3.rb
+++ b/lib/stack_master/aws_driver/s3.rb
@@ -17,10 +17,10 @@ def upload_files(bucket: nil, prefix: nil, region: nil, files: {})
 
         s3 = new_s3_client(region: region)
 
-        current_objects = s3.list_objects(
+        current_objects = s3.list_objects({
           prefix: prefix,
           bucket: bucket
-        ).map(&:contents).flatten.inject({}){|h,obj|
+        }).map(&:contents).flatten.inject({}){|h,obj|
           h.merge(obj.key => obj)
         }
 
@@ -38,12 +38,12 @@ def upload_files(bucket: nil, prefix: nil, region: nil, files: {})
           s3_uri = "s3://#{bucket}/#{object_key}"
           StackMaster.stdout.print "- #{File.basename(path)} => #{s3_uri} "
 
-          s3.put_object(
+          s3.put_object({
             bucket: bucket,
             key: object_key,
             body: body,
             metadata: { md5: compiled_template_md5 }
-          )
+          })
           StackMaster.stdout.puts "done."
         end
       end
@@ -61,7 +61,7 @@ def url(bucket:, prefix:, region:, template:)
       private
 
       def new_s3_client(region: nil)
-        Aws::S3::Client.new(region: region || @region)
+        Aws::S3::Client.new({ region: region || @region })
       end
     end
   end
diff --git a/lib/stack_master/change_set.rb b/lib/stack_master/change_set.rb
index 59e8f5b8..4201c6e7 100644
--- a/lib/stack_master/change_set.rb
+++ b/lib/stack_master/change_set.rb
@@ -25,12 +25,12 @@ def self.find(id)
     end
 
     def self.delete(id)
-      cf.delete_change_set(change_set_name: id)
+      cf.delete_change_set({ change_set_name: id })
     end
 
     def self.execute(id, stack_name)
-      cf.execute_change_set(change_set_name: id,
-                            stack_name: stack_name)
+      cf.execute_change_set({ change_set_name: id,
+                              stack_name: stack_name })
     end
 
     def self.cf
diff --git a/lib/stack_master/commands/resources.rb b/lib/stack_master/commands/resources.rb
index 16d8bda1..970d3ab1 100644
--- a/lib/stack_master/commands/resources.rb
+++ b/lib/stack_master/commands/resources.rb
@@ -17,7 +17,7 @@ def perform
       private
 
       def stack_resources
-        @stack_resources ||= cf.describe_stack_resources(stack_name: @stack_definition.stack_name).stack_resources
+        @stack_resources ||= cf.describe_stack_resources({ stack_name: @stack_definition.stack_name }).stack_resources
       rescue Aws::CloudFormation::Errors::ValidationError
         nil
       end
diff --git a/lib/stack_master/identity.rb b/lib/stack_master/identity.rb
index 00c6163b..752021fc 100644
--- a/lib/stack_master/identity.rb
+++ b/lib/stack_master/identity.rb
@@ -31,11 +31,11 @@ def region
     end
 
     def sts
-      @sts ||= Aws::STS::Client.new(region: region)
+      @sts ||= Aws::STS::Client.new({ region: region })
     end
 
     def iam
-      @iam ||= Aws::IAM::Client.new(region: region)
+      @iam ||= Aws::IAM::Client.new({ region: region })
     end
 
     def contains_account_id?(ids)
diff --git a/lib/stack_master/parameter_resolvers/acm_certificate.rb b/lib/stack_master/parameter_resolvers/acm_certificate.rb
index d9224185..d7e3c2e1 100644
--- a/lib/stack_master/parameter_resolvers/acm_certificate.rb
+++ b/lib/stack_master/parameter_resolvers/acm_certificate.rb
@@ -19,9 +19,9 @@ def resolve(domain_name)
       def all_certs
         certs = []
         next_token = nil
-        client = Aws::ACM::Client.new(region: @stack_definition.region)
+        client = Aws::ACM::Client.new({ region: @stack_definition.region })
         loop do
-          resp = client.list_certificates(certificate_statuses: ['ISSUED'], next_token: next_token)
+          resp = client.list_certificates({ certificate_statuses: ['ISSUED'], next_token: next_token })
           certs << resp.certificate_summary_list
           next_token = resp.next_token
           break if next_token.nil?
diff --git a/lib/stack_master/parameter_resolvers/ami_finder.rb b/lib/stack_master/parameter_resolvers/ami_finder.rb
index e9ca1856..a8168a10 100644
--- a/lib/stack_master/parameter_resolvers/ami_finder.rb
+++ b/lib/stack_master/parameter_resolvers/ami_finder.rb
@@ -19,7 +19,7 @@ def build_filters_from_hash(hash)
       end
 
       def find_latest_ami(filters, owners = ['self'])
-        images = ec2.describe_images(owners: owners, filters: filters).images
+        images = ec2.describe_images({ owners: owners, filters: filters }).images
         sorted_images = images.sort do |a, b|
           Time.parse(a.creation_date) <=> Time.parse(b.creation_date)
         end
@@ -29,8 +29,8 @@ def find_latest_ami(filters, owners = ['self'])
       private
 
       def ec2
-        @ec2 ||= Aws::EC2::Client.new(region: @region)
+        @ec2 ||= Aws::EC2::Client.new({ region: @region })
       end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/lib/stack_master/parameter_resolvers/latest_container.rb b/lib/stack_master/parameter_resolvers/latest_container.rb
index 3ca5a869..0c86bc31 100644
--- a/lib/stack_master/parameter_resolvers/latest_container.rb
+++ b/lib/stack_master/parameter_resolvers/latest_container.rb
@@ -14,7 +14,7 @@ def resolve(parameters)
         end
 
         @region = parameters['region'] || @stack_definition.region
-        ecr_client = Aws::ECR::Client.new(region: @region)
+        ecr_client = Aws::ECR::Client.new({ region: @region })
 
         images = fetch_images(parameters['repository_name'], parameters['registry_id'], ecr_client)
 
diff --git a/lib/stack_master/parameter_resolvers/parameter_store.rb b/lib/stack_master/parameter_resolvers/parameter_store.rb
index 20b58ee4..443a3ff9 100644
--- a/lib/stack_master/parameter_resolvers/parameter_store.rb
+++ b/lib/stack_master/parameter_resolvers/parameter_store.rb
@@ -11,11 +11,11 @@ def initialize(config, stack_definition)
 
       def resolve(value)
         begin
-          ssm = Aws::SSM::Client.new(region: @stack_definition.region)
-          resp = ssm.get_parameter(
+          ssm = Aws::SSM::Client.new({ region: @stack_definition.region })
+          resp = ssm.get_parameter({
             name: value,
             with_decryption: true
-          )
+          })
         rescue Aws::SSM::Errors::ParameterNotFound
           raise ParameterNotFound, "Unable to find #{value} in Parameter Store"
         end
diff --git a/lib/stack_master/parameter_resolvers/stack_output.rb b/lib/stack_master/parameter_resolvers/stack_output.rb
index d83492f0..80658cef 100644
--- a/lib/stack_master/parameter_resolvers/stack_output.rb
+++ b/lib/stack_master/parameter_resolvers/stack_output.rb
@@ -53,7 +53,7 @@ def find_stack(stack_name, region)
 
         @stacks.fetch(stack_key) do
           regional_cf = cf_for_region(unaliased_region)
-          cf_stack = regional_cf.describe_stacks(stack_name: stack_name).stacks.first
+          cf_stack = regional_cf.describe_stacks({ stack_name: stack_name }).stacks.first
           @stacks[stack_key] = cf_stack
         end
       end
diff --git a/lib/stack_master/role_assumer.rb b/lib/stack_master/role_assumer.rb
index 8ed4a6fd..f582cfbf 100644
--- a/lib/stack_master/role_assumer.rb
+++ b/lib/stack_master/role_assumer.rb
@@ -44,11 +44,11 @@ def with_temporary_cf_driver(&block)
     def assume_role_credentials(account, role)
       credentials_key = "#{account}:#{role}"
       @credentials.fetch(credentials_key) do
-        @credentials[credentials_key] = Aws::AssumeRoleCredentials.new(
+        @credentials[credentials_key] = Aws::AssumeRoleCredentials.new({
           region: StackMaster.cloud_formation_driver.region,
           role_arn: "arn:aws:iam::#{account}:role/#{role}",
           role_session_name: "stack-master-role-assumer"
-        )
+        })
       end
     end
   end
diff --git a/lib/stack_master/security_group_finder.rb b/lib/stack_master/security_group_finder.rb
index ba93a7bd..237009a5 100644
--- a/lib/stack_master/security_group_finder.rb
+++ b/lib/stack_master/security_group_finder.rb
@@ -4,7 +4,7 @@ class SecurityGroupFinder
     MultipleSecurityGroupsFound = Class.new(StandardError)
 
     def initialize(region)
-      @resource = Aws::EC2::Resource.new(region: region)
+      @resource = Aws::EC2::Resource.new({ region: region })
     end
 
     def find(reference)
diff --git a/lib/stack_master/sns_topic_finder.rb b/lib/stack_master/sns_topic_finder.rb
index 7177a60a..8de5b0ba 100644
--- a/lib/stack_master/sns_topic_finder.rb
+++ b/lib/stack_master/sns_topic_finder.rb
@@ -3,7 +3,7 @@ class SnsTopicFinder
     TopicNotFound = Class.new(StandardError)
 
     def initialize(region)
-      @resource = Aws::SNS::Resource.new(region: region)
+      @resource = Aws::SNS::Resource.new({ region: region })
     end
 
     def find(reference)
diff --git a/lib/stack_master/stack.rb b/lib/stack_master/stack.rb
index 99357dad..7977ce03 100644
--- a/lib/stack_master/stack.rb
+++ b/lib/stack_master/stack.rb
@@ -29,15 +29,15 @@ def parameters_with_defaults
 
     def self.find(region, stack_name)
       cf = StackMaster.cloud_formation_driver
-      cf_stack = cf.describe_stacks(stack_name: stack_name).stacks.first
+      cf_stack = cf.describe_stacks({ stack_name: stack_name }).stacks.first
       return unless cf_stack
       parameters = cf_stack.parameters.inject({}) do |params_hash, param_struct|
         params_hash[param_struct.parameter_key] = param_struct.parameter_value
         params_hash
       end
-      template_body ||= cf.get_template(stack_name: stack_name, template_stage: 'Original').template_body
+      template_body ||= cf.get_template({ stack_name: stack_name, template_stage: 'Original' }).template_body
       template_format = TemplateUtils.identify_template_format(template_body)
-      stack_policy_body ||= cf.get_stack_policy(stack_name: stack_name).stack_policy_body
+      stack_policy_body ||= cf.get_stack_policy({ stack_name: stack_name }).stack_policy_body
       outputs = cf_stack.outputs
 
       new(region: region,
diff --git a/spec/stack_master/aws_driver/s3_spec.rb b/spec/stack_master/aws_driver/s3_spec.rb
index 42f8c87d..2c4b5ab5 100644
--- a/spec/stack_master/aws_driver/s3_spec.rb
+++ b/spec/stack_master/aws_driver/s3_spec.rb
@@ -1,7 +1,7 @@
 RSpec.describe StackMaster::AwsDriver::S3 do
   let(:region) { 'us-east-1' }
   let(:bucket) { 'bucket' }
-  let(:s3) { Aws::S3::Client.new(stub_responses: true) }
+  let(:s3) { Aws::S3::Client.new({ stub_responses: true }) }
   subject(:s3_driver) { StackMaster::AwsDriver::S3.new }
 
   before do
@@ -16,7 +16,7 @@
     context 'when set_region is called' do
       it 'defaults to that region' do
         s3_driver.set_region('default')
-        expect(Aws::S3::Client).to receive(:new).with(region: 'default').and_return(s3)
+        expect(Aws::S3::Client).to receive(:new).with({ region: 'default' }).and_return(s3)
         files = {
           'template' => {
             path: 'spec/fixtures/templates/myapp_vpc.json',
@@ -43,10 +43,16 @@
       end
 
       it 'uploads files under a prefix' do
-        expect(s3).to receive(:put_object).with(bucket: 'bucket',
-                                                       key: 'prefix/template',
-                                                       body: 'file content',
-                                                       metadata: {md5: "d10b4c3ff123b26dc068d43a8bef2d23"})
+        expect(s3).to receive(:put_object).with(
+          {
+            bucket: 'bucket',
+            key: 'prefix/template',
+            body: 'file content',
+            metadata: {
+              md5: "d10b4c3ff123b26dc068d43a8bef2d23"
+            }
+          }
+        )
         s3_driver.upload_files(**options)
       end
     end
@@ -65,10 +71,16 @@
       end
 
       it 'uploads files under the bucket root' do
-        expect(s3).to receive(:put_object).with(bucket: 'bucket',
-                                                       key: 'template',
-                                                       body: 'file content',
-                                                       metadata: {md5: "d10b4c3ff123b26dc068d43a8bef2d23"})
+        expect(s3).to receive(:put_object).with(
+          {
+            bucket: 'bucket',
+            key: 'template',
+            body: 'file content',
+            metadata: {
+              md5: "d10b4c3ff123b26dc068d43a8bef2d23"
+            }
+          }
+        )
         s3_driver.upload_files(**options)
       end
     end
@@ -88,10 +100,16 @@
       end
 
       it 'uploads files under the prefix' do
-        expect(s3).to receive(:put_object).with(bucket: 'bucket',
-                                                       key: 'prefix/template',
-                                                       body: 'file content',
-                                                       metadata: {md5: "d10b4c3ff123b26dc068d43a8bef2d23"})
+        expect(s3).to receive(:put_object).with(
+          {
+            bucket: 'bucket',
+            key: 'prefix/template',
+            body: 'file content',
+            metadata: {
+              md5: "d10b4c3ff123b26dc068d43a8bef2d23"
+            }
+          }
+        )
         s3_driver.upload_files(**options)
       end
     end
@@ -115,14 +133,26 @@
       end
 
       it 'uploads all the files' do
-        expect(s3).to receive(:put_object).with(bucket: 'bucket',
-                                                       key: 'template1',
-                                                       body: 'file content',
-                                                       metadata: {md5: "d10b4c3ff123b26dc068d43a8bef2d23"})
-        expect(s3).to receive(:put_object).with(bucket: 'bucket',
-                                                       key: 'template2',
-                                                       body: 'file content',
-                                                       metadata: {md5: "d10b4c3ff123b26dc068d43a8bef2d23"})
+        expect(s3).to receive(:put_object).with(
+          {
+            bucket: 'bucket',
+            key: 'template1',
+            body: 'file content',
+            metadata: {
+              md5: "d10b4c3ff123b26dc068d43a8bef2d23"
+            }
+          }
+        )
+        expect(s3).to receive(:put_object).with(
+          {
+            bucket: 'bucket',
+            key: 'template2',
+            body: 'file content',
+            metadata: {
+              md5: "d10b4c3ff123b26dc068d43a8bef2d23"
+            }
+          }
+        )
         s3_driver.upload_files(**options)
       end
     end
diff --git a/spec/stack_master/change_set_spec.rb b/spec/stack_master/change_set_spec.rb
index fa2679ba..911a3eb6 100644
--- a/spec/stack_master/change_set_spec.rb
+++ b/spec/stack_master/change_set_spec.rb
@@ -21,22 +21,22 @@
 
     context 'successful response' do
       before do
-        allow(cf).to receive(:describe_change_set).with(change_set_name: 'id-1', next_token: nil).and_return(double(next_token: nil, changes: [], :changes= => nil, :next_token= => nil, status: 'CREATE_COMPLETE'))
+        allow(cf).to receive(:describe_change_set).with({ change_set_name: 'id-1', next_token: nil }).and_return(double(next_token: nil, changes: [], :changes= => nil, :next_token= => nil, status: 'CREATE_COMPLETE'))
       end
 
       it 'calls the create change set API with the addition of a name' do
         change_set = StackMaster::ChangeSet.create(stack_name: '123')
-        expect(cf).to have_received(:create_change_set).with(
+        expect(cf).to have_received(:create_change_set).with({
           stack_name: '123',
           change_set_name: change_set_name
-        )
+        })
         expect(change_set.failed?).to eq false
       end
     end
 
     context 'unsuccessful response' do
       before do
-        allow(cf).to receive(:describe_change_set).with(change_set_name: 'id-1', next_token: nil).and_return(double(next_token: nil, changes: [], :changes= => nil, :next_token= => nil, status: 'FAILED', status_reason: 'No changes'))
+        allow(cf).to receive(:describe_change_set).with({ change_set_name: 'id-1', next_token: nil }).and_return(double(next_token: nil, changes: [], :changes= => nil, :next_token= => nil, status: 'FAILED', status_reason: 'No changes'))
       end
 
       it 'is marked as failed' do
diff --git a/spec/stack_master/commands/apply_spec.rb b/spec/stack_master/commands/apply_spec.rb
index e9e8f182..b8a98076 100644
--- a/spec/stack_master/commands/apply_spec.rb
+++ b/spec/stack_master/commands/apply_spec.rb
@@ -248,7 +248,7 @@ def apply
       end
 
       it "deletes the stack" do
-        expect(cf).to receive(:delete_stack).with(stack_name: stack_name)
+        expect(cf).to receive(:delete_stack).with({ stack_name: stack_name })
         expect { apply }.to raise_error(StackMaster::CtrlC)
       end
     end
diff --git a/spec/stack_master/commands/delete_spec.rb b/spec/stack_master/commands/delete_spec.rb
index ec2f4d1d..300ea90d 100644
--- a/spec/stack_master/commands/delete_spec.rb
+++ b/spec/stack_master/commands/delete_spec.rb
@@ -8,7 +8,7 @@
 
   before do
     StackMaster.cloud_formation_driver.set_region(region)
-    allow(Aws::CloudFormation::Client).to receive(:new).with(region: region, retry_limit: 10).and_return(cf)
+    allow(Aws::CloudFormation::Client).to receive(:new).with({ region: region, retry_limit: 10 }).and_return(cf)
     allow(delete).to receive(:ask?).and_return('y')
     allow(StackMaster::StackEvents::Streamer).to receive(:stream)
   end
diff --git a/spec/stack_master/parameter_resolvers/acm_certificate_spec.rb b/spec/stack_master/parameter_resolvers/acm_certificate_spec.rb
index 928a6ff6..f28deda1 100644
--- a/spec/stack_master/parameter_resolvers/acm_certificate_spec.rb
+++ b/spec/stack_master/parameter_resolvers/acm_certificate_spec.rb
@@ -10,10 +10,15 @@
 
   context 'when a certificate is found' do
     before do
-      acm.stub_responses(:list_certificates, certificate_summary_list: [
-        { certificate_arn: 'arn:aws:acm:us-east-1:12345:certificate/abc', domain_name: 'abc' },
-        { certificate_arn: 'arn:aws:acm:us-east-1:12345:certificate/def', domain_name: 'def' }
-      ])
+      acm.stub_responses(
+        :list_certificates,
+        {
+          certificate_summary_list: [
+            { certificate_arn: 'arn:aws:acm:us-east-1:12345:certificate/abc', domain_name: 'abc' },
+            { certificate_arn: 'arn:aws:acm:us-east-1:12345:certificate/def', domain_name: 'def' }
+          ]
+        }
+      )
     end
 
     it 'returns the certificate' do
@@ -23,7 +28,7 @@
 
   context 'when no certificate is found' do
     before do
-      acm.stub_responses(:list_certificates, certificate_summary_list: [])
+      acm.stub_responses(:list_certificates, { certificate_summary_list: [] })
     end
 
     it 'raises an error' do
diff --git a/spec/stack_master/parameter_resolvers/ami_finder_spec.rb b/spec/stack_master/parameter_resolvers/ami_finder_spec.rb
index 7170a070..e3041a32 100644
--- a/spec/stack_master/parameter_resolvers/ami_finder_spec.rb
+++ b/spec/stack_master/parameter_resolvers/ami_finder_spec.rb
@@ -44,10 +44,15 @@
 
     context 'when matches are found' do
       before do
-        ec2.stub_responses(:describe_images, images: [
-          { image_id: '1', creation_date: '2015-01-02 00:00:00', tags: [{ key: 'my-tag', value: 'my-value' }] },
-          { image_id: '2', creation_date: '2015-01-03 00:00:00', tags: [{ key: 'my-tag', value: 'my-value' }] }
-        ])
+        ec2.stub_responses(
+          :describe_images,
+          {
+            images: [
+              { image_id: '1', creation_date: '2015-01-02 00:00:00', tags: [{ key: 'my-tag', value: 'my-value' }] },
+              { image_id: '2', creation_date: '2015-01-03 00:00:00', tags: [{ key: 'my-tag', value: 'my-value' }] }
+            ]
+          }
+        )
       end
 
       it 'returns the latest one' do
@@ -57,7 +62,7 @@
 
     context 'when no matches are found' do
       before do
-        ec2.stub_responses(:describe_images, images: [])
+        ec2.stub_responses(:describe_images, { images: [] })
       end
 
       it 'returns nil' do
diff --git a/spec/stack_master/parameter_resolvers/latest_ami_by_tags_spec.rb b/spec/stack_master/parameter_resolvers/latest_ami_by_tags_spec.rb
index 75e4621a..ae0c4fdb 100644
--- a/spec/stack_master/parameter_resolvers/latest_ami_by_tags_spec.rb
+++ b/spec/stack_master/parameter_resolvers/latest_ami_by_tags_spec.rb
@@ -10,10 +10,15 @@
 
   context 'when matches are found' do
     before do
-      ec2.stub_responses(:describe_images, images: [
-        { image_id: '1', creation_date: '2015-01-02 00:00:00', tags: [{ key: 'my-tag', value: 'my-value' }] },
-        { image_id: '2', creation_date: '2015-01-03 00:00:00', tags: [{ key: 'my-tag', value: 'my-value' }] }
-      ])
+      ec2.stub_responses(
+        :describe_images,
+        {
+          images: [
+            { image_id: '1', creation_date: '2015-01-02 00:00:00', tags: [{ key: 'my-tag', value: 'my-value' }] },
+            { image_id: '2', creation_date: '2015-01-03 00:00:00', tags: [{ key: 'my-tag', value: 'my-value' }] }
+          ]
+        }
+      )
     end
 
     it 'returns the latest one' do
@@ -23,7 +28,7 @@
 
   context 'when no matches are found' do
     before do
-      ec2.stub_responses(:describe_images, images: [])
+      ec2.stub_responses(:describe_images, { images: [] })
     end
 
     it 'returns nil' do
diff --git a/spec/stack_master/parameter_resolvers/latest_ami_spec.rb b/spec/stack_master/parameter_resolvers/latest_ami_spec.rb
index 48a161af..67fc1f84 100644
--- a/spec/stack_master/parameter_resolvers/latest_ami_spec.rb
+++ b/spec/stack_master/parameter_resolvers/latest_ami_spec.rb
@@ -10,10 +10,15 @@
 
   context 'when matches are found' do
     before do
-      ec2.stub_responses(:describe_images, images: [
-        { image_id: '1', creation_date: '2015-01-02 00:00:00', name: 'foo' },
-        { image_id: '2', creation_date: '2015-01-03 00:00:00', name: 'foo' }
-      ])
+      ec2.stub_responses(
+        :describe_images,
+        {
+          images: [
+            { image_id: '1', creation_date: '2015-01-02 00:00:00', name: 'foo' },
+            { image_id: '2', creation_date: '2015-01-03 00:00:00', name: 'foo' }
+          ]
+        }
+      )
     end
 
     it 'returns the latest one' do
@@ -23,7 +28,7 @@
 
   context 'when no matches are found' do
     before do
-      ec2.stub_responses(:describe_images, images: [])
+      ec2.stub_responses(:describe_images, { images: [] })
     end
 
     it 'returns nil' do
diff --git a/spec/stack_master/parameter_resolvers/latest_container_spec.rb b/spec/stack_master/parameter_resolvers/latest_container_spec.rb
index 76bb1b90..5333da53 100644
--- a/spec/stack_master/parameter_resolvers/latest_container_spec.rb
+++ b/spec/stack_master/parameter_resolvers/latest_container_spec.rb
@@ -10,10 +10,16 @@
 
   context 'when matches are found' do
     before do
-      ecr.stub_responses(:describe_images, next_token: nil, image_details: [
-        { registry_id: '012345678910', image_digest: 'sha256:decafc0ffee', image_pushed_at: Time.utc(2015,1,2,0,0), image_tags: ['v1'] },
-        { registry_id: '012345678910', image_digest: 'sha256:deadbeef', image_pushed_at: Time.utc(2015,1,3,0,0), image_tags: ['v2'] }
-      ])
+      ecr.stub_responses(
+        :describe_images,
+        {
+          next_token: nil,
+          image_details: [
+            { registry_id: '012345678910', image_digest: 'sha256:decafc0ffee', image_pushed_at: Time.utc(2015,1,2,0,0), image_tags: ['v1'] },
+            { registry_id: '012345678910', image_digest: 'sha256:deadbeef', image_pushed_at: Time.utc(2015,1,3,0,0), image_tags: ['v2'] }
+          ]
+        }
+      )
     end
 
     it 'returns the latest one' do
@@ -23,7 +29,7 @@
 
   context 'when no matches are found' do
     before do
-      ecr.stub_responses(:describe_images, next_token: nil, image_details: [])
+      ecr.stub_responses(:describe_images, { next_token: nil, image_details: [] })
     end
 
     it 'returns nil' do
@@ -33,10 +39,16 @@
 
   context 'when a tag is passed in' do
     before do
-      ecr.stub_responses(:describe_images, next_token: nil, image_details: [
-        { registry_id: '012345678910', image_digest: 'sha256:decafc0ffee', image_pushed_at: Time.utc(2015,1,2,0,0), image_tags: ['v1', 'production'] },
-        { registry_id: '012345678910', image_digest: 'sha256:deadbeef', image_pushed_at: Time.utc(2015,1,3,0,0), image_tags: ['v2'] }
-      ])
+      ecr.stub_responses(
+        :describe_images,
+        {
+          next_token: nil,
+          image_details: [
+            { registry_id: '012345678910', image_digest: 'sha256:decafc0ffee', image_pushed_at: Time.utc(2015,1,2,0,0), image_tags: ['v1', 'production'] },
+            { registry_id: '012345678910', image_digest: 'sha256:deadbeef', image_pushed_at: Time.utc(2015,1,3,0,0), image_tags: ['v2'] }
+          ]
+        }
+      )
     end
   
     context 'when image exists' do
@@ -54,13 +66,19 @@
 
   context 'when registry_id is passed in' do
     before do
-      ecr.stub_responses(:describe_images, next_token: nil, image_details: [
-        { registry_id: '012345678910', image_digest: 'sha256:decafc0ffee', image_pushed_at: Time.utc(2015,1,2,0,0), image_tags: ['v1'] },
-      ])
+      ecr.stub_responses(
+        :describe_images,
+        {
+          next_token: nil,
+          image_details: [
+            { registry_id: '012345678910', image_digest: 'sha256:decafc0ffee', image_pushed_at: Time.utc(2015,1,2,0,0), image_tags: ['v1'] },
+          ]
+        }
+      )
     end
 
     it 'passes registry_id to describe_images' do
-      expect(ecr).to receive(:describe_images).with(repository_name: "foo", registry_id: "012345678910", next_token: nil, filter: {:tag_status=>"TAGGED"})
+      expect(ecr).to receive(:describe_images).with({repository_name: "foo", registry_id: "012345678910", next_token: nil, filter: {:tag_status=>"TAGGED"}})
       resolver.resolve({'repository_name' => 'foo', 'registry_id' => '012345678910'})
     end
   end
diff --git a/spec/stack_master/parameter_resolvers/stack_output_spec.rb b/spec/stack_master/parameter_resolvers/stack_output_spec.rb
index ef0bf9e0..74ec2e0c 100644
--- a/spec/stack_master/parameter_resolvers/stack_output_spec.rb
+++ b/spec/stack_master/parameter_resolvers/stack_output_spec.rb
@@ -38,7 +38,7 @@ def resolve(value)
 
     before do
       allow(Aws::CloudFormation::Client).to receive(:new).and_return(cf)
-      cf.stub_responses(:describe_stacks, stacks: stacks)
+      cf.stub_responses(:describe_stacks, { stacks: stacks })
     end
 
     context 'the stack and output exist' do
@@ -53,13 +53,13 @@ def resolve(value)
       end
 
       it 'caches stacks for the lifetime of the instance' do
-        expect(cf).to receive(:describe_stacks).with(stack_name: 'my-stack').and_call_original.once
+        expect(cf).to receive(:describe_stacks).with({ stack_name: 'my-stack' }).and_call_original.once
         resolver.resolve(value)
         resolver.resolve(value)
       end
 
       it "caches stacks by region" do
-        expect(cf).to receive(:describe_stacks).with(stack_name: 'my-stack').and_call_original.twice
+        expect(cf).to receive(:describe_stacks).with({ stack_name: 'my-stack' }).and_call_original.twice
         resolver.resolve(value)
         resolver.resolve(value)
         resolver.resolve("ap-southeast-2:#{value}")
@@ -79,7 +79,7 @@ def resolve(value)
         end
 
         it "caches stacks by credentials" do
-          expect(cf).to receive(:describe_stacks).with(stack_name: 'my-stack').and_call_original.twice
+          expect(cf).to receive(:describe_stacks).with({ stack_name: 'my-stack' }).and_call_original.twice
           resolver.resolve(value)
           resolver.resolve(value)
           Aws.config[:credentials] = "my-credentials"
@@ -132,7 +132,7 @@ def resolve(value)
 
     before do
       allow(Aws::CloudFormation::Client).to receive(:new).and_return(cf)
-      cf.stub_responses(:describe_stacks, stacks: stacks)
+      cf.stub_responses(:describe_stacks, { stacks: stacks })
     end
 
     context 'the stack and output exist' do
diff --git a/spec/stack_master/role_assumer_spec.rb b/spec/stack_master/role_assumer_spec.rb
index cc6d071e..eea7769e 100644
--- a/spec/stack_master/role_assumer_spec.rb
+++ b/spec/stack_master/role_assumer_spec.rb
@@ -16,11 +16,11 @@
     end
 
     it 'calls the assume role API once' do
-      expect(Aws::AssumeRoleCredentials).to receive(:new).with(
+      expect(Aws::AssumeRoleCredentials).to receive(:new).with({
         region: instance_of(String),
         role_arn: role_arn,
         role_session_name: instance_of(String)
-      ).once
+      }).once
 
       assume_role
     end
@@ -34,11 +34,11 @@
     end
 
     it 'assumes the role before calling block' do
-      expect(Aws::AssumeRoleCredentials).to receive(:new).with(
+      expect(Aws::AssumeRoleCredentials).to receive(:new).with({
         region: instance_of(String),
         role_arn: role_arn,
         role_session_name: instance_of(String)
-      ).ordered
+      }).ordered
       expect(my_block).to receive(:call).ordered
 
       assume_role
@@ -46,11 +46,11 @@
 
     it "uses the cloudformation driver's region" do
       StackMaster.cloud_formation_driver.set_region('my-region')
-      expect(Aws::AssumeRoleCredentials).to receive(:new).with(
+      expect(Aws::AssumeRoleCredentials).to receive(:new).with({
         region: 'my-region',
         role_arn: instance_of(String),
         role_session_name: instance_of(String)
-      )
+      })
 
       assume_role
     end
@@ -130,11 +130,11 @@
     describe 'when called multiple times' do
       context 'with the same account and role' do
         it 'assumes the role once' do
-          expect(Aws::AssumeRoleCredentials).to receive(:new).with(
+          expect(Aws::AssumeRoleCredentials).to receive(:new).with({
             region: instance_of(String),
             role_arn: role_arn,
             role_session_name: instance_of(String)
-          ).once
+          }).once
 
           role_assumer.assume_role(account, role, &my_block)
           role_assumer.assume_role(account, role, &my_block)
@@ -143,16 +143,16 @@
 
       context 'with a different account' do
         it 'assumes each role once' do
-          expect(Aws::AssumeRoleCredentials).to receive(:new).with(
+          expect(Aws::AssumeRoleCredentials).to receive(:new).with({
             region: instance_of(String),
             role_arn: role_arn,
             role_session_name: instance_of(String)
-          ).once
-          expect(Aws::AssumeRoleCredentials).to receive(:new).with(
+          }).once
+          expect(Aws::AssumeRoleCredentials).to receive(:new).with({
             region: instance_of(String),
             role_arn: "arn:aws:iam::another-account:role/#{role}",
             role_session_name: instance_of(String)
-          ).once
+          }).once
 
           role_assumer.assume_role(account, role, &my_block)
           role_assumer.assume_role('another-account', role, &my_block)
@@ -161,16 +161,16 @@
 
       context 'with a different role' do
         it 'assumes each role once' do
-          expect(Aws::AssumeRoleCredentials).to receive(:new).with(
+          expect(Aws::AssumeRoleCredentials).to receive(:new).with({
             region: instance_of(String),
             role_arn: role_arn,
             role_session_name: instance_of(String)
-          ).once
-          expect(Aws::AssumeRoleCredentials).to receive(:new).with(
+          }).once
+          expect(Aws::AssumeRoleCredentials).to receive(:new).with({
             region: instance_of(String),
             role_arn: "arn:aws:iam::#{account}:role/another-role",
             role_session_name: instance_of(String)
-          ).once
+          }).once
 
           role_assumer.assume_role(account, role, &my_block)
           role_assumer.assume_role(account, 'another-role', &my_block)
diff --git a/spec/stack_master/stack_spec.rb b/spec/stack_master/stack_spec.rb
index e6ff5514..d3a799a7 100644
--- a/spec/stack_master/stack_spec.rb
+++ b/spec/stack_master/stack_spec.rb
@@ -19,9 +19,24 @@
         ]
       }
       before do
-        cf.stub_responses(:describe_stacks, stacks: [{stack_id: stack_id, stack_name: stack_name, creation_time: Time.now, stack_status: 'UPDATE_COMPLETE', parameters: parameters, notification_arns: ['test_arn'], role_arn: 'test_service_role_arn'}])
-        cf.stub_responses(:get_template, template_body: "{}")
-        cf.stub_responses(:get_stack_policy, stack_policy_body: stack_policy_body)
+        cf.stub_responses(
+          :describe_stacks,
+          {
+            stacks: [
+              {
+                stack_id: stack_id,
+                stack_name: stack_name,
+                creation_time: Time.now,
+                stack_status: 'UPDATE_COMPLETE',
+                parameters: parameters,
+                notification_arns: ['test_arn'],
+                role_arn: 'test_service_role_arn'
+              }
+            ]
+          }
+        )
+        cf.stub_responses(:get_template, { template_body: "{}" })
+        cf.stub_responses(:get_stack_policy, { stack_policy_body: stack_policy_body })
       end
 
       it 'returns a stack object with a stack_id' do
@@ -62,7 +77,7 @@
 
     context 'when CF returns no stacks' do
       before do
-        cf.stub_responses(:describe_stacks, stacks: [])
+        cf.stub_responses(:describe_stacks, { stacks: [] })
       end
 
       it 'returns nil' do
diff --git a/spec/support/aws_stubs.rb b/spec/support/aws_stubs.rb
index 6e17da5e..7b90e294 100644
--- a/spec/support/aws_stubs.rb
+++ b/spec/support/aws_stubs.rb
@@ -2,18 +2,21 @@
 
 module AwsHelpers
   def stub_drift_detection(stack_drift_detection_id: "1", stack_drift_status: "IN_SYNC")
-    cfn.stub_responses(:detect_stack_drift,
-                       stack_drift_detection_id: stack_drift_detection_id)
-    cfn.stub_responses(:describe_stack_drift_detection_status,
-                       stack_id: "1",
-                       timestamp: Time.now,
-                       stack_drift_detection_id: stack_drift_detection_id,
-                       stack_drift_status: stack_drift_status,
-                       detection_status: "DETECTION_COMPLETE")
+    cfn.stub_responses(:detect_stack_drift, { stack_drift_detection_id: stack_drift_detection_id })
+    cfn.stub_responses(
+      :describe_stack_drift_detection_status,
+      {
+        stack_id: "1",
+        timestamp: Time.now,
+        stack_drift_detection_id: stack_drift_detection_id,
+        stack_drift_status: stack_drift_status,
+        detection_status: "DETECTION_COMPLETE"
+      }
+    )
   end
 
   def stub_stack_resource_drift(stack_name:, stack_resource_drifts:)
-    cfn.stub_responses(:describe_stack_resource_drifts, stack_resource_drifts: stack_resource_drifts)
+    cfn.stub_responses(:describe_stack_resource_drifts, { stack_resource_drifts: stack_resource_drifts })
   end
 end