diff --git a/Gemfile b/Gemfile
index 2a5f647..df32188 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 group :development do
   gem 'translations-manager', git: 'https://github.com/discourse/translations-manager.git'
 end
diff --git a/app/serializers/concerns/topic_answer_mixin.rb b/app/serializers/concerns/topic_answer_mixin.rb
index a767ab9..b3c5fc7 100644
--- a/app/serializers/concerns/topic_answer_mixin.rb
+++ b/app/serializers/concerns/topic_answer_mixin.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module TopicAnswerMixin
   def self.included(klass)
     klass.attributes :has_accepted_answer, :can_have_answer
diff --git a/bin/pull_translations.rb b/bin/pull_translations.rb
index a4052d8..ecfee12 100755
--- a/bin/pull_translations.rb
+++ b/bin/pull_translations.rb
@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 require 'translations_manager'
 
diff --git a/plugin.rb b/plugin.rb
index 8a66f83..3000b04 100644
--- a/plugin.rb
+++ b/plugin.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # name: discourse-solved
 # about: Add a solved button to answers on Discourse
 # version: 0.1
diff --git a/spec/integration/solved_spec.rb b/spec/integration/solved_spec.rb
index 845af00..5d47aca 100644
--- a/spec/integration/solved_spec.rb
+++ b/spec/integration/solved_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 RSpec.describe "Managing Posts solved status" do
diff --git a/spec/models/site_spec.rb b/spec/models/site_spec.rb
index 2e4e27b..9b815b4 100644
--- a/spec/models/site_spec.rb
+++ b/spec/models/site_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 require_dependency 'site'
 
diff --git a/spec/requests/topics_controller_spec.rb b/spec/requests/topics_controller_spec.rb
index 106bdf0..f653b54 100644
--- a/spec/requests/topics_controller_spec.rb
+++ b/spec/requests/topics_controller_spec.rb
@@ -1,50 +1,52 @@
-require 'rails_helper'
-
-RSpec.describe TopicsController do
-  let(:p1) { Fabricate(:post, like_count: 1) }
-  let(:topic) { p1.topic }
-  let(:p2) { Fabricate(:post, like_count: 2, topic: topic, user: Fabricate(:user)) }
-
-  def schema_json(answerCount)
-    if answerCount > 0
-      answer_json = ',"acceptedAnswer":{"@type":"Answer","text":"%{answer_text}","upvoteCount":%{answer_likes},"dateCreated":"%{answered_at}","url":"%{answer_url}","author":{"@type":"Person","name":"%{username2}"}}' % {
-        answer_text: p2.excerpt,
-        answer_likes: p2.like_count,
-        answered_at: p2.created_at.as_json,
-        answer_url: p2.full_url,
-        username2: p2.user&.username
-      }
-    else
-      answer_json = ""
-    end
-
-    '<script type="application/ld+json">{"@context":"http://schema.org","@type":"QAPage","name":"%{title}","mainEntity":{"@type":"Question","name":"%{title}","text":"%{question_text}","upvoteCount":%{question_likes},"answerCount":%{answerCount},"dateCreated":"%{created_at}","author":{"@type":"Person","name":"%{username1}"}%{answer_json}}}</script>' % {
-      title: topic.title,
-      question_text: p1.excerpt,
-      question_likes: p1.like_count,
-      answerCount: answerCount,
-      created_at: topic.created_at.as_json,
-      username1: topic.user&.name,
-      answer_json: answer_json
-    }
-  end
-
-  before do
-    SiteSetting.allow_solved_on_all_topics = true
-  end
-
-  it 'should include correct schema information in header' do
-    get "/t/#{topic.slug}/#{topic.id}"
-
-    expect(response.body).to include(schema_json(0))
-
-    p2.custom_fields["is_accepted_answer"] = true
-    p2.save_custom_fields
-    topic.custom_fields["accepted_answer_post_id"] = p2.id
-    topic.save_custom_fields
-
-    get "/t/#{topic.slug}/#{topic.id}"
-
-    expect(response.body).to include(schema_json(1))
-  end
-end
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe TopicsController do
+  let(:p1) { Fabricate(:post, like_count: 1) }
+  let(:topic) { p1.topic }
+  let(:p2) { Fabricate(:post, like_count: 2, topic: topic, user: Fabricate(:user)) }
+
+  def schema_json(answerCount)
+    if answerCount > 0
+      answer_json = ',"acceptedAnswer":{"@type":"Answer","text":"%{answer_text}","upvoteCount":%{answer_likes},"dateCreated":"%{answered_at}","url":"%{answer_url}","author":{"@type":"Person","name":"%{username2}"}}' % {
+        answer_text: p2.excerpt,
+        answer_likes: p2.like_count,
+        answered_at: p2.created_at.as_json,
+        answer_url: p2.full_url,
+        username2: p2.user&.username
+      }
+    else
+      answer_json = ""
+    end
+
+    '<script type="application/ld+json">{"@context":"http://schema.org","@type":"QAPage","name":"%{title}","mainEntity":{"@type":"Question","name":"%{title}","text":"%{question_text}","upvoteCount":%{question_likes},"answerCount":%{answerCount},"dateCreated":"%{created_at}","author":{"@type":"Person","name":"%{username1}"}%{answer_json}}}</script>' % {
+      title: topic.title,
+      question_text: p1.excerpt,
+      question_likes: p1.like_count,
+      answerCount: answerCount,
+      created_at: topic.created_at.as_json,
+      username1: topic.user&.name,
+      answer_json: answer_json
+    }
+  end
+
+  before do
+    SiteSetting.allow_solved_on_all_topics = true
+  end
+
+  it 'should include correct schema information in header' do
+    get "/t/#{topic.slug}/#{topic.id}"
+
+    expect(response.body).to include(schema_json(0))
+
+    p2.custom_fields["is_accepted_answer"] = true
+    p2.save_custom_fields
+    topic.custom_fields["accepted_answer_post_id"] = p2.id
+    topic.save_custom_fields
+
+    get "/t/#{topic.slug}/#{topic.id}"
+
+    expect(response.body).to include(schema_json(1))
+  end
+end
diff --git a/spec/serializers/topic_answer_mixin_spec.rb b/spec/serializers/topic_answer_mixin_spec.rb
index ec92b98..64b0faa 100644
--- a/spec/serializers/topic_answer_mixin_spec.rb
+++ b/spec/serializers/topic_answer_mixin_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 describe TopicAnswerMixin do