diff --git a/lib/elbas/aws/launch_template.rb b/lib/elbas/aws/launch_template.rb
index c23a45a..a878f05 100644
--- a/lib/elbas/aws/launch_template.rb
+++ b/lib/elbas/aws/launch_template.rb
@@ -16,6 +16,12 @@ def update(ami)
           source_version: self.version
         }).launch_template_version
 
+        response = aws_client.modify_launch_template({
+          default_version: latest.version_number.to_s,
+          launch_template_id: latest.launch_template_id
+        })
+        return unless response.successful?
+
         self.class.new(
           latest&.launch_template_id,
           latest&.launch_template_name,
@@ -29,4 +35,4 @@ def aws_namespace
         end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/spec/aws/launch_template_spec.rb b/spec/aws/launch_template_spec.rb
index 46ba8c8..bbe87ee 100644
--- a/spec/aws/launch_template_spec.rb
+++ b/spec/aws/launch_template_spec.rb
@@ -3,7 +3,9 @@
 
   before do
     webmock :post, %r{ec2.(.*).amazonaws.com\/\z} => 'CreateLaunchTemplateVersion.200.xml',
-      with: Hash[body: /Action=CreateLaunchTemplateVersion/]
+                   with: Hash[body: /Action=CreateLaunchTemplateVersion/]
+    webmock :post, %r{ec2.(.*).amazonaws.com\/\z} => 'ModifyLaunchTemplate.200.xml',
+                   with: Hash[body: /Action=ModifyLaunchTemplate/]
   end
 
   describe '#initialize' do
@@ -42,6 +44,13 @@
         .with(body: %r{LaunchTemplateId=test-lt&SourceVersion=1})
     end
 
+    it 'updates default launch template version' do
+      subject.update double(:ami, id: 'ami-123')
+      expect(WebMock)
+        .to have_requested(:post, /ec2/)
+        .with(body: %r{Action=ModifyLaunchTemplate})
+    end
+
     it 'returns a new launch template' do
       launch_template = subject.update double(:ami, id: 'ami-123')
       expect(launch_template.id).to eq 'lt-1234567890'
@@ -49,4 +58,4 @@
       expect(launch_template.version).to eq 123
     end
   end
-end
\ No newline at end of file
+end
diff --git a/spec/support/stubs/ModifyLaunchTemplate.200.xml b/spec/support/stubs/ModifyLaunchTemplate.200.xml
new file mode 100644
index 0000000..c8f81fe
--- /dev/null
+++ b/spec/support/stubs/ModifyLaunchTemplate.200.xml
@@ -0,0 +1,11 @@
+<ModifyLaunchTemplateResponse 
+  xmlns="https://awscli.amazonaws.com/v2/documentation/api/latest/reference/ec2/modify-launch-template.html">
+  <LaunchTemplate>
+        <CreateTime>2017-12-01T13:35:46.000Z</CreateTime>
+        <CreatedBy>arn:aws:iam::123456789012:root</CreatedBy>
+        <DefaultVersionNumber>2</DefaultVersionNumber>
+        <LatestVersionNumber>2</LatestVersionNumber>
+        <LaunchTemplateId>lt-0abcd290751193123</LaunchTemplateId>
+        <LaunchTemplateName>WebServers</LaunchTemplateName>
+     </LaunchTemplate>
+</ModifyLaunchTemplateResponse>