diff --git a/.rubocop.yml b/.rubocop.yml
index 5ae90526..c778bc07 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -118,3 +118,6 @@ Metrics/BlockLength:
 
 Performance/RegexpMatch:
   Enabled: false
+
+Style/IndentHeredoc:
+  Enabled: false
diff --git a/benchmarks/payload_truncator_string_encoding.rb b/benchmarks/payload_truncator_string_encoding.rb
index 0e45403f..0d20554e 100644
--- a/benchmarks/payload_truncator_string_encoding.rb
+++ b/benchmarks/payload_truncator_string_encoding.rb
@@ -1,4 +1,5 @@
 # coding: utf-8
+
 require_relative 'benchmark_helpers'
 
 require 'securerandom'
diff --git a/lib/airbrake-ruby/filters.rb b/lib/airbrake-ruby/filters.rb
index 0423e8f3..1ef3feb5 100644
--- a/lib/airbrake-ruby/filters.rb
+++ b/lib/airbrake-ruby/filters.rb
@@ -5,6 +5,6 @@ module Filters
     ##
     # @return [Array<Symbol>] parts of a Notice's payload that can be modified
     #   by various filters
-    FILTERABLE_KEYS = [:environment, :session, :params].freeze
+    FILTERABLE_KEYS = %i[environment session params].freeze
   end
 end
diff --git a/lib/airbrake-ruby/notice.rb b/lib/airbrake-ruby/notice.rb
index 820af360..dfed0668 100644
--- a/lib/airbrake-ruby/notice.rb
+++ b/lib/airbrake-ruby/notice.rb
@@ -44,12 +44,12 @@ class Notice
 
     # @return [Array<Symbol>] the list of keys that can be be overwritten with
     #   {Airbrake::Notice#[]=}
-    WRITABLE_KEYS = [
-      :notifier,
-      :context,
-      :environment,
-      :session,
-      :params
+    WRITABLE_KEYS = %i[
+      notifier
+      context
+      environment
+      session
+      params
     ].freeze
 
     ##
diff --git a/spec/airbrake_spec.rb b/spec/airbrake_spec.rb
index 656c31c7..308111a0 100644
--- a/spec/airbrake_spec.rb
+++ b/spec/airbrake_spec.rb
@@ -94,7 +94,7 @@
         notifiers = described_class.instance_variable_get(:@notifiers)
 
         expect(notifiers).to be_a(Hash)
-        expect(notifiers.keys).to eq([:default, :bingo])
+        expect(notifiers.keys).to eq(%i[default bingo])
         expect(notifiers.values).to all(satisfy { |v| v.is_a?(Airbrake::Notifier) })
       end
 
diff --git a/spec/config/validator_spec.rb b/spec/config/validator_spec.rb
index 673f38da..261af4ca 100644
--- a/spec/config/validator_spec.rb
+++ b/spec/config/validator_spec.rb
@@ -12,9 +12,9 @@
       end
 
       it "sets correct error message" do
-        expect { subject.valid_project_id? }.
-          to change { subject.error_message }.
-          to(/:project_id is required/)
+        expect { subject.valid_project_id? }.to(
+          change { subject.error_message }.to(/:project_id is required/)
+        )
       end
     end
 
@@ -28,8 +28,9 @@
 
         it "sets correct error message" do
           expect { subject.valid_project_id? }.
-            to change { subject.error_message }.
-            to(/:project_id is required/)
+            to(
+              change { subject.error_message }.to(/:project_id is required/)
+            )
         end
       end
 
@@ -41,9 +42,9 @@
         end
 
         it "sets correct error message" do
-          expect { subject.valid_project_id? }.
-            to change { subject.error_message }.
-            to(/:project_id is required/)
+          expect { subject.valid_project_id? }.to(
+            change { subject.error_message }.to(/:project_id is required/)
+          )
         end
       end
 
@@ -55,7 +56,7 @@
         end
 
         it "doesn't set the error message" do
-          expect { subject.valid_project_id? }.not_to change { subject.error_message }
+          expect { subject.valid_project_id? }.not_to(change { subject.error_message })
         end
       end
     end
@@ -68,7 +69,7 @@
       end
 
       it "doesn't set the error message" do
-        expect { subject.valid_project_id? }.not_to change { subject.error_message }
+        expect { subject.valid_project_id? }.not_to(change { subject.error_message })
       end
     end
   end
@@ -97,7 +98,7 @@
         end
 
         it "doesn't set the error message" do
-          expect { subject.valid_project_key? }.not_to change { subject.error_message }
+          expect { subject.valid_project_key? }.not_to(change { subject.error_message })
         end
       end
     end
@@ -110,9 +111,9 @@
       end
 
       it "sets correct error message" do
-        expect { subject.valid_project_key? }.
-          to change { subject.error_message }.
-          to(/:project_key is required/)
+        expect { subject.valid_project_key? }.to(
+          change { subject.error_message }.to(/:project_key is required/)
+        )
       end
     end
   end
@@ -126,7 +127,7 @@
       end
 
       it "doesn't set the error message" do
-        expect { subject.valid_environment? }.not_to change { subject.error_message }
+        expect { subject.valid_environment? }.not_to(change { subject.error_message })
       end
     end
 
@@ -139,9 +140,10 @@
         end
 
         it "sets the error message" do
-          expect { subject.valid_environment? }.
-            to change { subject.error_message }.
-            to(/the 'environment' option must be configured with a Symbol/)
+          expect { subject.valid_environment? }.to(
+            change { subject.error_message }.
+              to(/the 'environment' option must be configured with a Symbol/)
+          )
         end
       end
 
@@ -153,7 +155,7 @@
         end
 
         it "doesn't set the error message" do
-          expect { subject.valid_environment? }.not_to change { subject.error_message }
+          expect { subject.valid_environment? }.not_to(change { subject.error_message })
         end
       end
 
@@ -165,7 +167,7 @@
         end
 
         it "doesn't set the error message" do
-          expect { subject.valid_environment? }.not_to change { subject.error_message }
+          expect { subject.valid_environment? }.not_to(change { subject.error_message })
         end
       end
 
@@ -181,7 +183,7 @@
         end
 
         it "doesn't set the error message" do
-          expect { subject.valid_environment? }.not_to change { subject.error_message }
+          expect { subject.valid_environment? }.not_to(change { subject.error_message })
         end
       end
     end
diff --git a/spec/config_spec.rb b/spec/config_spec.rb
index eaba459c..318f3945 100644
--- a/spec/config_spec.rb
+++ b/spec/config_spec.rb
@@ -221,7 +221,7 @@
         context "and when 'ignore_environments' contains Strings" do
           it "returns true" do
             config.environment = :bango
-            config.ignore_environments = %w(bango)
+            config.ignore_environments = %w[bango]
 
             expect(config.ignored_environment?).to be_truthy
           end
diff --git a/spec/filter_chain_spec.rb b/spec/filter_chain_spec.rb
index 55de58bc..85433390 100644
--- a/spec/filter_chain_spec.rb
+++ b/spec/filter_chain_spec.rb
@@ -181,7 +181,7 @@
 
           expect(notice[:errors].first[:file]).to be_nil
           expect { @chain.refine(notice) }.
-            not_to change { notice[:errors].first[:file] }
+            not_to(change { notice[:errors].first[:file] })
         end
       end
 
@@ -200,7 +200,7 @@
 
           expect(notice[:errors].first[:file]).to be_nil
           expect { filter_chain.refine(notice) }.
-            not_to change { notice[:errors].first[:file] }
+            not_to(change { notice[:errors].first[:file] })
         end
       end
     end
diff --git a/spec/notifier_spec.rb b/spec/notifier_spec.rb
index a6c92745..2632c5bf 100644
--- a/spec/notifier_spec.rb
+++ b/spec/notifier_spec.rb
@@ -1,4 +1,5 @@
 # coding: utf-8
+
 require 'spec_helper'
 
 RSpec.describe Airbrake::Notifier do
@@ -405,7 +406,7 @@ def to_json(*)
       notifier.close
     end
 
-    it "respawns workers on fork()", skip: %w(jruby rbx).include?(RUBY_ENGINE) do
+    it "respawns workers on fork()", skip: %w[jruby rbx].include?(RUBY_ENGINE) do
       out = StringIO.new
       notifier = described_class.new(airbrake_params.merge(logger: Logger.new(out)))
 
@@ -445,7 +446,7 @@ def to_json(*)
     end
 
     it "accepts multiple filters" do
-      [:bingo, :bongo, :bash].each do |key|
+      %i[bingo bongo bash].each do |key|
         @airbrake.add_filter do |notice|
           notice[:params][key] = '[Filtered]'.freeze if notice[:params][key]
         end
diff --git a/spec/notifier_spec/options_spec.rb b/spec/notifier_spec/options_spec.rb
index 033abc76..420dd9d0 100644
--- a/spec/notifier_spec/options_spec.rb
+++ b/spec/notifier_spec/options_spec.rb
@@ -201,7 +201,7 @@ def expect_a_request_with_body(body)
       context "when the current env and notify envs are the same" do
         params = {
           environment: :development,
-          ignore_environments: [:production, :development]
+          ignore_environments: %i[production development]
         }
 
         include_examples 'ignored notice', params
@@ -217,7 +217,7 @@ def expect_a_request_with_body(body)
       end
 
       context "when the current env is not set and notify envs are present" do
-        params = { ignore_environments: [:production, :development] }
+        params = { ignore_environments: %i[production development] }
 
         include_examples 'sent notice', params
       end
diff --git a/spec/notifier_spec/whitelist_keys_spec.rb b/spec/notifier_spec/whitelist_keys_spec.rb
index 3ca1d194..998b3fa9 100644
--- a/spec/notifier_spec/whitelist_keys_spec.rb
+++ b/spec/notifier_spec/whitelist_keys_spec.rb
@@ -91,14 +91,14 @@ def expect_a_request_with_body(body)
 
       include_examples(
         'whitelisting',
-        %w(bongo bish),
+        %w[bongo bish],
         bingo: 'bango', bongo: { bish: 'bash' }
       )
     end
 
     context "and it is a recursive hash" do
       it "errors when nested hashes are not filtered" do
-        whitelist = airbrake_params.merge(whitelist_keys: %w(bingo bango))
+        whitelist = airbrake_params.merge(whitelist_keys: %w[bingo bango])
         notifier = Airbrake::Notifier.new(whitelist)
 
         bongo = { bingo: {} }
@@ -196,7 +196,7 @@ def expect_a_request_with_body(body)
 
   describe "context/url" do
     let(:notifier) do
-      Airbrake::Notifier.new(airbrake_params.merge(whitelist_keys: %w(bish)))
+      Airbrake::Notifier.new(airbrake_params.merge(whitelist_keys: %w[bish]))
     end
 
     context "given a standard URL" do
diff --git a/spec/payload_truncator_spec.rb b/spec/payload_truncator_spec.rb
index d9d9efdf..f1dacefd 100644
--- a/spec/payload_truncator_spec.rb
+++ b/spec/payload_truncator_spec.rb
@@ -1,4 +1,5 @@
 # coding: utf-8
+
 require 'spec_helper'
 
 RSpec.describe Airbrake::PayloadTruncator do
@@ -216,13 +217,13 @@
 
         context "of short strings" do
           let(:params) do
-            { bingo: %w(foo bar baz), bango: 'bongo', bish: 'bash' }
+            { bingo: %w[foo bar baz], bango: 'bongo', bish: 'bash' }
           end
 
           it "truncates long strings in the array, but not short ones" do
             @truncator.truncate_object(params)
             expect(params).
-              to eq(bingo: %w(foo bar baz), bango: 'bongo', bish: 'bash')
+              to eq(bingo: %w[foo bar baz], bango: 'bongo', bish: 'bash')
           end
         end