diff --git a/.rubocop.yml b/.rubocop.yml
index 938b22da..6548e1a3 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,4 +1,5 @@
 inherit_gem:
   rubocop-github:
     - config/default.yml
-require: rubocop-performance
+plugins:
+  - rubocop-performance
diff --git a/lib/secure_headers.rb b/lib/secure_headers.rb
index 6426e538..4b288c8e 100644
--- a/lib/secure_headers.rb
+++ b/lib/secure_headers.rb
@@ -208,7 +208,7 @@ def raise_on_unknown_target(target)
 
     def config_and_target(request, target)
       config = config_for(request)
-      target = guess_target(config) unless target
+      target ||= guess_target(config)
       raise_on_unknown_target(target)
       [config, target]
     end
diff --git a/lib/secure_headers/headers/clear_site_data.rb b/lib/secure_headers/headers/clear_site_data.rb
index 0fdc0c2a..05d26a8f 100644
--- a/lib/secure_headers/headers/clear_site_data.rb
+++ b/lib/secure_headers/headers/clear_site_data.rb
@@ -11,43 +11,41 @@ class ClearSiteData
     EXECUTION_CONTEXTS = "executionContexts".freeze
     ALL_TYPES = [CACHE, COOKIES, STORAGE, EXECUTION_CONTEXTS]
 
-    class << self
-      # Public: make an clear-site-data header name, value pair
-      #
-      # Returns nil if not configured, returns header name and value if configured.
-      def make_header(config = nil, user_agent = nil)
-        case config
-        when nil, OPT_OUT, []
-          # noop
-        when Array
-          [HEADER_NAME, make_header_value(config)]
-        when true
-          [HEADER_NAME, make_header_value(ALL_TYPES)]
-        end
+    # Public: make an clear-site-data header name, value pair
+    #
+    # Returns nil if not configured, returns header name and value if configured.
+    def self.make_header(config = nil, user_agent = nil)
+      case config
+      when nil, OPT_OUT, []
+        # noop
+      when Array
+        [HEADER_NAME, make_header_value(config)]
+      when true
+        [HEADER_NAME, make_header_value(ALL_TYPES)]
       end
+    end
 
-      def validate_config!(config)
-        case config
-        when nil, OPT_OUT, true
-          # valid
-        when Array
-          unless config.all? { |t| t.is_a?(String) }
-            raise ClearSiteDataConfigError.new("types must be Strings")
-          end
-        else
-          raise ClearSiteDataConfigError.new("config must be an Array of Strings or `true`")
+    def self.validate_config!(config)
+      case config
+      when nil, OPT_OUT, true
+        # valid
+      when Array
+        unless config.all? { |t| t.is_a?(String) }
+          raise ClearSiteDataConfigError.new("types must be Strings")
         end
+      else
+        raise ClearSiteDataConfigError.new("config must be an Array of Strings or `true`")
       end
+    end
 
-      # Public: Transform a clear-site-data config (an Array of Strings) into a
-      # String that can be used as the value for the clear-site-data header.
-      #
-      # types - An Array of String of types of data to clear.
-      #
-      # Returns a String of quoted values that are comma separated.
-      def make_header_value(types)
-        types.map { |t| %("#{t}") }.join(", ")
-      end
+    # Public: Transform a clear-site-data config (an Array of Strings) into a
+    # String that can be used as the value for the clear-site-data header.
+    #
+    # types - An Array of String of types of data to clear.
+    #
+    # Returns a String of quoted values that are comma separated.
+    def self.make_header_value(types)
+      types.map { |t| %("#{t}") }.join(", ")
     end
   end
 end
diff --git a/lib/secure_headers/headers/cookie.rb b/lib/secure_headers/headers/cookie.rb
index 9d3f7cd1..8f78612c 100644
--- a/lib/secure_headers/headers/cookie.rb
+++ b/lib/secure_headers/headers/cookie.rb
@@ -7,10 +7,8 @@ module SecureHeaders
   class CookiesConfigError < StandardError; end
   class Cookie
 
-    class << self
-      def validate_config!(config)
-        CookiesConfig.new(config).validate!
-      end
+    def self.validate_config!(config)
+      CookiesConfig.new(config).validate!
     end
 
     attr_reader :raw_cookie, :config
diff --git a/lib/secure_headers/headers/expect_certificate_transparency.rb b/lib/secure_headers/headers/expect_certificate_transparency.rb
index 4b7272dd..582e8a05 100644
--- a/lib/secure_headers/headers/expect_certificate_transparency.rb
+++ b/lib/secure_headers/headers/expect_certificate_transparency.rb
@@ -9,31 +9,29 @@ class ExpectCertificateTransparency
     REQUIRED_MAX_AGE_ERROR      = "max-age is a required directive.".freeze
     INVALID_MAX_AGE_ERROR       = "max-age must be a number.".freeze
 
-    class << self
-      # Public: Generate a expect-ct header.
-      #
-      # Returns nil if not configured, returns header name and value if
-      # configured.
-      def make_header(config, use_agent = nil)
-        return if config.nil? || config == OPT_OUT
+    # Public: Generate a expect-ct header.
+    #
+    # Returns nil if not configured, returns header name and value if
+    # configured.
+    def self.make_header(config, use_agent = nil)
+      return if config.nil? || config == OPT_OUT
 
-        header = new(config)
-        [HEADER_NAME, header.value]
-      end
+      header = new(config)
+      [HEADER_NAME, header.value]
+    end
 
-      def validate_config!(config)
-        return if config.nil? || config == OPT_OUT
-        raise ExpectCertificateTransparencyConfigError.new(INVALID_CONFIGURATION_ERROR) unless config.is_a? Hash
+    def self.validate_config!(config)
+      return if config.nil? || config == OPT_OUT
+      raise ExpectCertificateTransparencyConfigError.new(INVALID_CONFIGURATION_ERROR) unless config.is_a? Hash
 
-        unless [true, false, nil].include?(config[:enforce])
-          raise ExpectCertificateTransparencyConfigError.new(INVALID_ENFORCE_VALUE_ERROR)
-        end
+      unless [true, false, nil].include?(config[:enforce])
+        raise ExpectCertificateTransparencyConfigError.new(INVALID_ENFORCE_VALUE_ERROR)
+      end
 
-        if !config[:max_age]
-          raise ExpectCertificateTransparencyConfigError.new(REQUIRED_MAX_AGE_ERROR)
-        elsif config[:max_age].to_s !~ /\A\d+\z/
-          raise ExpectCertificateTransparencyConfigError.new(INVALID_MAX_AGE_ERROR)
-        end
+      if !config[:max_age]
+        raise ExpectCertificateTransparencyConfigError.new(REQUIRED_MAX_AGE_ERROR)
+      elsif config[:max_age].to_s !~ /\A\d+\z/
+        raise ExpectCertificateTransparencyConfigError.new(INVALID_MAX_AGE_ERROR)
       end
     end
 
diff --git a/lib/secure_headers/headers/referrer_policy.rb b/lib/secure_headers/headers/referrer_policy.rb
index a4589117..2094656c 100644
--- a/lib/secure_headers/headers/referrer_policy.rb
+++ b/lib/secure_headers/headers/referrer_policy.rb
@@ -15,29 +15,27 @@ class ReferrerPolicy
       unsafe-url
     )
 
-    class << self
-      # Public: generate an Referrer Policy header.
-      #
-      # Returns a default header if no configuration is provided, or a
-      # header name and value based on the config.
-      def make_header(config = nil, user_agent = nil)
-        return if config == OPT_OUT
-        config ||= DEFAULT_VALUE
-        [HEADER_NAME, Array(config).join(", ")]
-      end
+    # Public: generate an Referrer Policy header.
+    #
+    # Returns a default header if no configuration is provided, or a
+    # header name and value based on the config.
+    def self.make_header(config = nil, user_agent = nil)
+      return if config == OPT_OUT
+      config ||= DEFAULT_VALUE
+      [HEADER_NAME, Array(config).join(", ")]
+    end
 
-      def validate_config!(config)
-        case config
-        when nil, OPT_OUT
-          # valid
-        when String, Array
-          config = Array(config)
-          unless config.all? { |t| t.is_a?(String) && VALID_POLICIES.include?(t.downcase) }
-            raise ReferrerPolicyConfigError.new("Value can only be one or more of #{VALID_POLICIES.join(", ")}")
-          end
-        else
-          raise TypeError.new("Must be a string or array of strings. Found #{config.class}: #{config}")
+    def self.validate_config!(config)
+      case config
+      when nil, OPT_OUT
+        # valid
+      when String, Array
+        config = Array(config)
+        unless config.all? { |t| t.is_a?(String) && VALID_POLICIES.include?(t.downcase) }
+          raise ReferrerPolicyConfigError.new("Value can only be one or more of #{VALID_POLICIES.join(", ")}")
         end
+      else
+        raise TypeError.new("Must be a string or array of strings. Found #{config.class}: #{config}")
       end
     end
   end
diff --git a/lib/secure_headers/headers/strict_transport_security.rb b/lib/secure_headers/headers/strict_transport_security.rb
index 3d78a484..eaf46cb6 100644
--- a/lib/secure_headers/headers/strict_transport_security.rb
+++ b/lib/secure_headers/headers/strict_transport_security.rb
@@ -9,21 +9,19 @@ class StrictTransportSecurity
     VALID_STS_HEADER = /\Amax-age=\d+(; includeSubdomains)?(; preload)?\z/i
     MESSAGE = "The config value supplied for the HSTS header was invalid. Must match #{VALID_STS_HEADER}"
 
-    class << self
-      # Public: generate an hsts header name, value pair.
-      #
-      # Returns a default header if no configuration is provided, or a
-      # header name and value based on the config.
-      def make_header(config = nil, user_agent = nil)
-        return if config == OPT_OUT
-        [HEADER_NAME, config || DEFAULT_VALUE]
-      end
+    # Public: generate an hsts header name, value pair.
+    #
+    # Returns a default header if no configuration is provided, or a
+    # header name and value based on the config.
+    def self.make_header(config = nil, user_agent = nil)
+      return if config == OPT_OUT
+      [HEADER_NAME, config || DEFAULT_VALUE]
+    end
 
-      def validate_config!(config)
-        return if config.nil? || config == OPT_OUT
-        raise TypeError.new("Must be a string. Found #{config.class}: #{config} #{config.class}") unless config.is_a?(String)
-        raise STSConfigError.new(MESSAGE) unless config =~ VALID_STS_HEADER
-      end
+    def self.validate_config!(config)
+      return if config.nil? || config == OPT_OUT
+      raise TypeError.new("Must be a string. Found #{config.class}: #{config} #{config.class}") unless config.is_a?(String)
+      raise STSConfigError.new(MESSAGE) unless config =~ VALID_STS_HEADER
     end
   end
 end
diff --git a/lib/secure_headers/headers/x_content_type_options.rb b/lib/secure_headers/headers/x_content_type_options.rb
index 96f8d314..773bad82 100644
--- a/lib/secure_headers/headers/x_content_type_options.rb
+++ b/lib/secure_headers/headers/x_content_type_options.rb
@@ -6,22 +6,20 @@ class XContentTypeOptions
     HEADER_NAME = "x-content-type-options".freeze
     DEFAULT_VALUE = "nosniff"
 
-    class << self
-      # Public: generate an X-Content-Type-Options header.
-      #
-      # Returns a default header if no configuration is provided, or a
-      # header name and value based on the config.
-      def make_header(config = nil, user_agent = nil)
-        return if config == OPT_OUT
-        [HEADER_NAME, config || DEFAULT_VALUE]
-      end
+    # Public: generate an X-Content-Type-Options header.
+    #
+    # Returns a default header if no configuration is provided, or a
+    # header name and value based on the config.
+    def self.make_header(config = nil, user_agent = nil)
+      return if config == OPT_OUT
+      [HEADER_NAME, config || DEFAULT_VALUE]
+    end
 
-      def validate_config!(config)
-        return if config.nil? || config == OPT_OUT
-        raise TypeError.new("Must be a string. Found #{config.class}: #{config}") unless config.is_a?(String)
-        unless config.casecmp(DEFAULT_VALUE) == 0
-          raise XContentTypeOptionsConfigError.new("Value can only be nil or 'nosniff'")
-        end
+    def self.validate_config!(config)
+      return if config.nil? || config == OPT_OUT
+      raise TypeError.new("Must be a string. Found #{config.class}: #{config}") unless config.is_a?(String)
+      unless config.casecmp(DEFAULT_VALUE) == 0
+        raise XContentTypeOptionsConfigError.new("Value can only be nil or 'nosniff'")
       end
     end
   end
diff --git a/lib/secure_headers/headers/x_download_options.rb b/lib/secure_headers/headers/x_download_options.rb
index 1eb1356a..0042e9d0 100644
--- a/lib/secure_headers/headers/x_download_options.rb
+++ b/lib/secure_headers/headers/x_download_options.rb
@@ -5,22 +5,20 @@ class XDownloadOptions
     HEADER_NAME = "x-download-options".freeze
     DEFAULT_VALUE = "noopen"
 
-    class << self
-      # Public: generate an x-download-options header.
-      #
-      # Returns a default header if no configuration is provided, or a
-      # header name and value based on the config.
-      def make_header(config = nil, user_agent = nil)
-        return if config == OPT_OUT
-        [HEADER_NAME, config || DEFAULT_VALUE]
-      end
+    # Public: generate an x-download-options header.
+    #
+    # Returns a default header if no configuration is provided, or a
+    # header name and value based on the config.
+    def self.make_header(config = nil, user_agent = nil)
+      return if config == OPT_OUT
+      [HEADER_NAME, config || DEFAULT_VALUE]
+    end
 
-      def validate_config!(config)
-        return if config.nil? || config == OPT_OUT
-        raise TypeError.new("Must be a string. Found #{config.class}: #{config}") unless config.is_a?(String)
-        unless config.casecmp(DEFAULT_VALUE) == 0
-          raise XDOConfigError.new("Value can only be nil or 'noopen'")
-        end
+    def self.validate_config!(config)
+      return if config.nil? || config == OPT_OUT
+      raise TypeError.new("Must be a string. Found #{config.class}: #{config}") unless config.is_a?(String)
+      unless config.casecmp(DEFAULT_VALUE) == 0
+        raise XDOConfigError.new("Value can only be nil or 'noopen'")
       end
     end
   end
diff --git a/lib/secure_headers/headers/x_frame_options.rb b/lib/secure_headers/headers/x_frame_options.rb
index 636e3bfa..9788ca3e 100644
--- a/lib/secure_headers/headers/x_frame_options.rb
+++ b/lib/secure_headers/headers/x_frame_options.rb
@@ -10,22 +10,20 @@ class XFrameOptions
     DEFAULT_VALUE = SAMEORIGIN
     VALID_XFO_HEADER = /\A(#{SAMEORIGIN}\z|#{DENY}\z|#{ALLOW_ALL}\z|#{ALLOW_FROM}[:\s])/i
 
-    class << self
-      # Public: generate an X-Frame-Options header.
-      #
-      # Returns a default header if no configuration is provided, or a
-      # header name and value based on the config.
-      def make_header(config = nil, user_agent = nil)
-        return if config == OPT_OUT
-        [HEADER_NAME, config || DEFAULT_VALUE]
-      end
+    # Public: generate an X-Frame-Options header.
+    #
+    # Returns a default header if no configuration is provided, or a
+    # header name and value based on the config.
+    def self.make_header(config = nil, user_agent = nil)
+      return if config == OPT_OUT
+      [HEADER_NAME, config || DEFAULT_VALUE]
+    end
 
-      def validate_config!(config)
-        return if config.nil? || config == OPT_OUT
-        raise TypeError.new("Must be a string. Found #{config.class}: #{config}") unless config.is_a?(String)
-        unless config =~ VALID_XFO_HEADER
-          raise XFOConfigError.new("Value must be SAMEORIGIN|DENY|ALLOW-FROM:|ALLOWALL")
-        end
+    def self.validate_config!(config)
+      return if config.nil? || config == OPT_OUT
+      raise TypeError.new("Must be a string. Found #{config.class}: #{config}") unless config.is_a?(String)
+      unless config =~ VALID_XFO_HEADER
+        raise XFOConfigError.new("Value must be SAMEORIGIN|DENY|ALLOW-FROM:|ALLOWALL")
       end
     end
   end
diff --git a/lib/secure_headers/headers/x_permitted_cross_domain_policies.rb b/lib/secure_headers/headers/x_permitted_cross_domain_policies.rb
index a34dd58f..4ca81b68 100644
--- a/lib/secure_headers/headers/x_permitted_cross_domain_policies.rb
+++ b/lib/secure_headers/headers/x_permitted_cross_domain_policies.rb
@@ -6,22 +6,20 @@ class XPermittedCrossDomainPolicies
     DEFAULT_VALUE = "none"
     VALID_POLICIES = %w(all none master-only by-content-type by-ftp-filename)
 
-    class << self
-      # Public: generate an x-permitted-cross-domain-policies header.
-      #
-      # Returns a default header if no configuration is provided, or a
-      # header name and value based on the config.
-      def make_header(config = nil, user_agent = nil)
-        return if config == OPT_OUT
-        [HEADER_NAME, config || DEFAULT_VALUE]
-      end
+    # Public: generate an x-permitted-cross-domain-policies header.
+    #
+    # Returns a default header if no configuration is provided, or a
+    # header name and value based on the config.
+    def self.make_header(config = nil, user_agent = nil)
+      return if config == OPT_OUT
+      [HEADER_NAME, config || DEFAULT_VALUE]
+    end
 
-      def validate_config!(config)
-        return if config.nil? || config == OPT_OUT
-        raise TypeError.new("Must be a string. Found #{config.class}: #{config}") unless config.is_a?(String)
-        unless VALID_POLICIES.include?(config.downcase)
-          raise XPCDPConfigError.new("Value can only be one of #{VALID_POLICIES.join(', ')}")
-        end
+    def self.validate_config!(config)
+      return if config.nil? || config == OPT_OUT
+      raise TypeError.new("Must be a string. Found #{config.class}: #{config}") unless config.is_a?(String)
+      unless VALID_POLICIES.include?(config.downcase)
+        raise XPCDPConfigError.new("Value can only be one of #{VALID_POLICIES.join(', ')}")
       end
     end
   end
diff --git a/lib/secure_headers/headers/x_xss_protection.rb b/lib/secure_headers/headers/x_xss_protection.rb
index bd5b7faa..756bc4c3 100644
--- a/lib/secure_headers/headers/x_xss_protection.rb
+++ b/lib/secure_headers/headers/x_xss_protection.rb
@@ -6,21 +6,19 @@ class XXssProtection
     DEFAULT_VALUE = "0".freeze
     VALID_X_XSS_HEADER = /\A[01](; mode=block)?(; report=.*)?\z/
 
-    class << self
-      # Public: generate an X-Xss-Protection header.
-      #
-      # Returns a default header if no configuration is provided, or a
-      # header name and value based on the config.
-      def make_header(config = nil, user_agent = nil)
-        return if config == OPT_OUT
-        [HEADER_NAME, config || DEFAULT_VALUE]
-      end
+    # Public: generate an X-Xss-Protection header.
+    #
+    # Returns a default header if no configuration is provided, or a
+    # header name and value based on the config.
+    def self.make_header(config = nil, user_agent = nil)
+      return if config == OPT_OUT
+      [HEADER_NAME, config || DEFAULT_VALUE]
+    end
 
-      def validate_config!(config)
-        return if config.nil? || config == OPT_OUT
-        raise TypeError.new("Must be a string. Found #{config.class}: #{config}") unless config.is_a?(String)
-        raise XXssProtectionConfigError.new("Invalid format (see VALID_X_XSS_HEADER)") unless config.to_s =~ VALID_X_XSS_HEADER
-      end
+    def self.validate_config!(config)
+      return if config.nil? || config == OPT_OUT
+      raise TypeError.new("Must be a string. Found #{config.class}: #{config}") unless config.is_a?(String)
+      raise XXssProtectionConfigError.new("Invalid format (see VALID_X_XSS_HEADER)") unless config.to_s =~ VALID_X_XSS_HEADER
     end
   end
 end
diff --git a/spec/lib/secure_headers/configuration_spec.rb b/spec/lib/secure_headers/configuration_spec.rb
index 73e9b16b..1c613658 100644
--- a/spec/lib/secure_headers/configuration_spec.rb
+++ b/spec/lib/secure_headers/configuration_spec.rb
@@ -22,7 +22,9 @@ module SecureHeaders
       configuration = Configuration.dup
       expect(original_configuration).not_to be(configuration)
       Configuration::CONFIG_ATTRIBUTES.each do |attr|
-        expect(original_configuration.send(attr)).to eq(configuration.send(attr))
+        # rubocop:disable GitHub/AvoidObjectSendWithDynamicMethod
+        expect(original_configuration.public_send(attr)).to eq(configuration.public_send(attr))
+        # rubocop:enable GitHub/AvoidObjectSendWithDynamicMethod
       end
     end
 
@@ -97,7 +99,7 @@ module SecureHeaders
     end
 
     it "gives cookies a default config" do
-      expect(Configuration.default.cookies).to eq({httponly: true, secure: true, samesite: {lax: true}})
+      expect(Configuration.default.cookies).to eq({ httponly: true, secure: true, samesite: { lax: true } })
     end
 
     it "allows OPT_OUT" do
@@ -111,11 +113,11 @@ module SecureHeaders
 
     it "allows me to be explicit too" do
       Configuration.default do |config|
-        config.cookies = {httponly: true, secure: true, samesite: {lax: false}}
+        config.cookies = { httponly: true, secure: true, samesite: { lax: false } }
       end
 
       config = Configuration.dup
-      expect(config.cookies).to eq({httponly: true, secure: true, samesite: {lax: false}})
+      expect(config.cookies).to eq({ httponly: true, secure: true, samesite: { lax: false } })
     end
   end
 end
diff --git a/spec/lib/secure_headers/headers/content_security_policy_spec.rb b/spec/lib/secure_headers/headers/content_security_policy_spec.rb
index 37cb62a7..c16e70a2 100644
--- a/spec/lib/secure_headers/headers/content_security_policy_spec.rb
+++ b/spec/lib/secure_headers/headers/content_security_policy_spec.rb
@@ -3,7 +3,7 @@
 
 module SecureHeaders
   describe ContentSecurityPolicy do
-    let (:default_opts) do
+    let(:default_opts) do
       {
         default_src: %w(https:),
         img_src: %w(https: data:),
@@ -167,47 +167,47 @@ module SecureHeaders
       end
 
       it "supports strict-dynamic" do
-        csp = ContentSecurityPolicy.new({default_src: %w('self'), script_src: [ContentSecurityPolicy::STRICT_DYNAMIC], script_nonce: 123456})
+        csp = ContentSecurityPolicy.new({ default_src: %w('self'), script_src: [ContentSecurityPolicy::STRICT_DYNAMIC], script_nonce: 123456 })
         expect(csp.value).to eq("default-src 'self'; script-src 'strict-dynamic' 'nonce-123456' 'unsafe-inline'")
       end
 
       it "supports strict-dynamic and opting out of the appended 'unsafe-inline'" do
-        csp = ContentSecurityPolicy.new({default_src: %w('self'), script_src: [ContentSecurityPolicy::STRICT_DYNAMIC], script_nonce: 123456, disable_nonce_backwards_compatibility: true })
+        csp = ContentSecurityPolicy.new({ default_src: %w('self'), script_src: [ContentSecurityPolicy::STRICT_DYNAMIC], script_nonce: 123456, disable_nonce_backwards_compatibility: true })
         expect(csp.value).to eq("default-src 'self'; script-src 'strict-dynamic' 'nonce-123456'")
       end
 
       it "supports script-src-elem directive" do
-        csp = ContentSecurityPolicy.new({script_src: %w('self'), script_src_elem: %w('self')})
+        csp = ContentSecurityPolicy.new({ script_src: %w('self'), script_src_elem: %w('self') })
         expect(csp.value).to eq("script-src 'self'; script-src-elem 'self'")
       end
 
       it "supports script-src-attr directive" do
-        csp = ContentSecurityPolicy.new({script_src: %w('self'), script_src_attr: %w('self')})
+        csp = ContentSecurityPolicy.new({ script_src: %w('self'), script_src_attr: %w('self') })
         expect(csp.value).to eq("script-src 'self'; script-src-attr 'self'")
       end
 
       it "supports style-src-elem directive" do
-        csp = ContentSecurityPolicy.new({style_src: %w('self'), style_src_elem: %w('self')})
+        csp = ContentSecurityPolicy.new({ style_src: %w('self'), style_src_elem: %w('self') })
         expect(csp.value).to eq("style-src 'self'; style-src-elem 'self'")
       end
 
       it "supports style-src-attr directive" do
-        csp = ContentSecurityPolicy.new({style_src: %w('self'), style_src_attr: %w('self')})
+        csp = ContentSecurityPolicy.new({ style_src: %w('self'), style_src_attr: %w('self') })
         expect(csp.value).to eq("style-src 'self'; style-src-attr 'self'")
       end
 
       it "supports trusted-types directive" do
-        csp = ContentSecurityPolicy.new({trusted_types: %w(blahblahpolicy)})
+        csp = ContentSecurityPolicy.new({ trusted_types: %w(blahblahpolicy) })
         expect(csp.value).to eq("trusted-types blahblahpolicy")
       end
 
       it "supports trusted-types directive with 'none'" do
-        csp = ContentSecurityPolicy.new({trusted_types: %w('none')})
+        csp = ContentSecurityPolicy.new({ trusted_types: %w('none') })
         expect(csp.value).to eq("trusted-types 'none'")
       end
 
       it "allows duplicate policy names in trusted-types directive" do
-        csp = ContentSecurityPolicy.new({trusted_types: %w(blahblahpolicy 'allow-duplicates')})
+        csp = ContentSecurityPolicy.new({ trusted_types: %w(blahblahpolicy 'allow-duplicates') })
         expect(csp.value).to eq("trusted-types blahblahpolicy 'allow-duplicates'")
       end
     end
diff --git a/spec/lib/secure_headers/headers/cookie_spec.rb b/spec/lib/secure_headers/headers/cookie_spec.rb
index cdb24246..b0a9152b 100644
--- a/spec/lib/secure_headers/headers/cookie_spec.rb
+++ b/spec/lib/secure_headers/headers/cookie_spec.rb
@@ -35,7 +35,7 @@ module SecureHeaders
 
       context "when configured with a Hash" do
         it "flags cookies as Secure when whitelisted" do
-          cookie = Cookie.new(raw_cookie, secure: { only: ["_session"]}, httponly: OPT_OUT, samesite: OPT_OUT)
+          cookie = Cookie.new(raw_cookie, secure: { only: ["_session"] }, httponly: OPT_OUT, samesite: OPT_OUT)
           expect(cookie.to_s).to eq("_session=thisisatest; secure")
         end
 
@@ -56,7 +56,7 @@ module SecureHeaders
 
       context "when configured with a Hash" do
         it "flags cookies as HttpOnly when whitelisted" do
-          cookie = Cookie.new(raw_cookie, httponly: { only: ["_session"]}, secure: OPT_OUT, samesite: OPT_OUT)
+          cookie = Cookie.new(raw_cookie, httponly: { only: ["_session"] }, secure: OPT_OUT, samesite: OPT_OUT)
           expect(cookie.to_s).to eq("_session=thisisatest; HttpOnly")
         end
 
@@ -75,7 +75,7 @@ module SecureHeaders
         end
 
         it "flags SameSite=#{flag} when configured with a boolean" do
-          cookie = Cookie.new(raw_cookie, samesite: { flag.downcase.to_sym => true}, secure: OPT_OUT, httponly: OPT_OUT)
+          cookie = Cookie.new(raw_cookie, samesite: { flag.downcase.to_sym => true }, secure: OPT_OUT, httponly: OPT_OUT)
           expect(cookie.to_s).to eq("_session=thisisatest; SameSite=#{flag}")
         end
 
@@ -86,7 +86,7 @@ module SecureHeaders
       end
 
       it "flags SameSite=Strict when configured with a boolean" do
-        cookie = Cookie.new(raw_cookie, {samesite: { strict: true}, secure: OPT_OUT, httponly: OPT_OUT})
+        cookie = Cookie.new(raw_cookie, { samesite: { strict: true }, secure: OPT_OUT, httponly: OPT_OUT })
         expect(cookie.to_s).to eq("_session=thisisatest; SameSite=Strict")
       end
 
@@ -146,7 +146,7 @@ module SecureHeaders
       (cookie_options - [flag]).each do |other_flag|
         it "raises an exception when SameSite #{flag} and #{other_flag} enforcement modes are configured with booleans" do
           expect do
-            Cookie.validate_config!(samesite: { flag => true, other_flag => true})
+            Cookie.validate_config!(samesite: { flag => true, other_flag => true })
           end.to raise_error(CookiesConfigError)
         end
       end
diff --git a/spec/lib/secure_headers/headers/policy_management_spec.rb b/spec/lib/secure_headers/headers/policy_management_spec.rb
index c621e88e..99065744 100644
--- a/spec/lib/secure_headers/headers/policy_management_spec.rb
+++ b/spec/lib/secure_headers/headers/policy_management_spec.rb
@@ -8,7 +8,7 @@ module SecureHeaders
       Configuration.default
     end
 
-    let (:default_opts) do
+    let(:default_opts) do
       {
         default_src: %w(https:),
         img_src: %w(https: data:),
diff --git a/spec/lib/secure_headers/middleware_spec.rb b/spec/lib/secure_headers/middleware_spec.rb
index b3925f85..f46a6979 100644
--- a/spec/lib/secure_headers/middleware_spec.rb
+++ b/spec/lib/secure_headers/middleware_spec.rb
@@ -42,7 +42,7 @@ module SecureHeaders
       end
       context "cookies should be flagged" do
         it "flags cookies as secure" do
-          Configuration.default { |config| config.cookies = {secure: true, httponly: OPT_OUT, samesite: OPT_OUT} }
+          Configuration.default { |config| config.cookies = { secure: true, httponly: OPT_OUT, samesite: OPT_OUT } }
           request = Rack::Request.new("HTTPS" => "on")
           _, env = cookie_middleware.call request.env
           expect(env["Set-Cookie"]).to eq("foo=bar; secure")
@@ -62,7 +62,7 @@ module SecureHeaders
 
       context "cookies should not be flagged" do
         it "does not flags cookies as secure" do
-          Configuration.default { |config| config.cookies = {secure: OPT_OUT, httponly: OPT_OUT, samesite: OPT_OUT}  }
+          Configuration.default { |config| config.cookies = { secure: OPT_OUT, httponly: OPT_OUT, samesite: OPT_OUT } }
           request = Rack::Request.new("HTTPS" => "on")
           _, env = cookie_middleware.call request.env
           expect(env["Set-Cookie"]).to eq("foo=bar")
@@ -75,7 +75,7 @@ module SecureHeaders
         reset_config
       end
       it "flags cookies from configuration" do
-        Configuration.default { |config| config.cookies = { secure: true, httponly: true, samesite: { lax: true} } }
+        Configuration.default { |config| config.cookies = { secure: true, httponly: true, samesite: { lax: true } } }
         request = Rack::Request.new("HTTPS" => "on")
         _, env = cookie_middleware.call request.env
 
@@ -85,7 +85,7 @@ module SecureHeaders
       it "flags cookies with a combination of SameSite configurations" do
         cookie_middleware = Middleware.new(lambda { |env| [200, env.merge("Set-Cookie" => ["_session=foobar", "_guest=true"]), "app"] })
 
-        Configuration.default { |config| config.cookies = { samesite: { lax: { except: ["_session"] }, strict: { only: ["_session"] } }, httponly: OPT_OUT, secure: OPT_OUT} }
+        Configuration.default { |config| config.cookies = { samesite: { lax: { except: ["_session"] }, strict: { only: ["_session"] } }, httponly: OPT_OUT, secure: OPT_OUT } }
         request = Rack::Request.new("HTTPS" => "on")
         _, env = cookie_middleware.call request.env
 
diff --git a/spec/lib/secure_headers_spec.rb b/spec/lib/secure_headers_spec.rb
index fd66d487..76d51baf 100644
--- a/spec/lib/secure_headers_spec.rb
+++ b/spec/lib/secure_headers_spec.rb
@@ -54,7 +54,7 @@ module SecureHeaders
     describe "#header_hash_for" do
       it "allows you to opt out of individual headers via API" do
         Configuration.default do |config|
-          config.csp = { default_src: %w('self'), script_src: %w('self')}
+          config.csp = { default_src: %w('self'), script_src: %w('self') }
           config.csp_report_only = config.csp
         end
         SecureHeaders.opt_out_of_header(request, :csp)
@@ -174,11 +174,11 @@ module SecureHeaders
           end
 
           Configuration.named_append(:moar_default_sources) do |request|
-            { default_src: %w(https:), style_src: %w('self')}
+            { default_src: %w(https:), style_src: %w('self') }
           end
 
           Configuration.named_append(:how_about_a_script_src_too) do |request|
-            { script_src: %w('unsafe-inline')}
+            { script_src: %w('unsafe-inline') }
           end
 
           SecureHeaders.use_content_security_policy_named_append(request, :moar_default_sources)
@@ -318,7 +318,7 @@ module SecureHeaders
                 default_src: %w('self'),
                 script_src: %w('self')
               }
-              config.csp_report_only = config.csp.merge({script_src: %w(foo.com)})
+              config.csp_report_only = config.csp.merge({ script_src: %w(foo.com) })
             end
 
             hash = SecureHeaders.header_hash_for(request)
@@ -342,42 +342,42 @@ module SecureHeaders
           end
 
           it "allows appending to the enforced policy" do
-            SecureHeaders.append_content_security_policy_directives(request, {script_src: %w(anothercdn.com)}, :enforced)
+            SecureHeaders.append_content_security_policy_directives(request, { script_src: %w(anothercdn.com) }, :enforced)
             hash = SecureHeaders.header_hash_for(request)
             expect(hash["content-security-policy"]).to eq("default-src 'self'; script-src 'self' anothercdn.com")
             expect(hash["content-security-policy-report-only"]).to eq("default-src 'self'; script-src 'self'")
           end
 
           it "allows appending to the report only policy" do
-            SecureHeaders.append_content_security_policy_directives(request, {script_src: %w(anothercdn.com)}, :report_only)
+            SecureHeaders.append_content_security_policy_directives(request, { script_src: %w(anothercdn.com) }, :report_only)
             hash = SecureHeaders.header_hash_for(request)
             expect(hash["content-security-policy"]).to eq("default-src 'self'; script-src 'self'")
             expect(hash["content-security-policy-report-only"]).to eq("default-src 'self'; script-src 'self' anothercdn.com")
           end
 
           it "allows appending to both policies" do
-            SecureHeaders.append_content_security_policy_directives(request, {script_src: %w(anothercdn.com)}, :both)
+            SecureHeaders.append_content_security_policy_directives(request, { script_src: %w(anothercdn.com) }, :both)
             hash = SecureHeaders.header_hash_for(request)
             expect(hash["content-security-policy"]).to eq("default-src 'self'; script-src 'self' anothercdn.com")
             expect(hash["content-security-policy-report-only"]).to eq("default-src 'self'; script-src 'self' anothercdn.com")
           end
 
           it "allows overriding the enforced policy" do
-            SecureHeaders.override_content_security_policy_directives(request, {script_src: %w(anothercdn.com)}, :enforced)
+            SecureHeaders.override_content_security_policy_directives(request, { script_src: %w(anothercdn.com) }, :enforced)
             hash = SecureHeaders.header_hash_for(request)
             expect(hash["content-security-policy"]).to eq("default-src 'self'; script-src anothercdn.com")
             expect(hash["content-security-policy-report-only"]).to eq("default-src 'self'; script-src 'self'")
           end
 
           it "allows overriding the report only policy" do
-            SecureHeaders.override_content_security_policy_directives(request, {script_src: %w(anothercdn.com)}, :report_only)
+            SecureHeaders.override_content_security_policy_directives(request, { script_src: %w(anothercdn.com) }, :report_only)
             hash = SecureHeaders.header_hash_for(request)
             expect(hash["content-security-policy"]).to eq("default-src 'self'; script-src 'self'")
             expect(hash["content-security-policy-report-only"]).to eq("default-src 'self'; script-src anothercdn.com")
           end
 
           it "allows overriding both policies" do
-            SecureHeaders.override_content_security_policy_directives(request, {script_src: %w(anothercdn.com)}, :both)
+            SecureHeaders.override_content_security_policy_directives(request, { script_src: %w(anothercdn.com) }, :both)
             hash = SecureHeaders.header_hash_for(request)
             expect(hash["content-security-policy"]).to eq("default-src 'self'; script-src anothercdn.com")
             expect(hash["content-security-policy-report-only"]).to eq("default-src 'self'; script-src anothercdn.com")
@@ -392,7 +392,7 @@ module SecureHeaders
                   script_src: %w('self')
                 }
               end
-              SecureHeaders.append_content_security_policy_directives(request, {script_src: %w(anothercdn.com)})
+              SecureHeaders.append_content_security_policy_directives(request, { script_src: %w(anothercdn.com) })
 
               hash = SecureHeaders.header_hash_for(request)
               expect(hash["content-security-policy"]).to eq("default-src 'self'; script-src 'self' anothercdn.com")
@@ -408,7 +408,7 @@ module SecureHeaders
                   script_src: %w('self')
                 }
               end
-              SecureHeaders.append_content_security_policy_directives(request, {script_src: %w(anothercdn.com)})
+              SecureHeaders.append_content_security_policy_directives(request, { script_src: %w(anothercdn.com) })
 
               hash = SecureHeaders.header_hash_for(request)
               expect(hash["content-security-policy-report-only"]).to eq("default-src 'self'; script-src 'self' anothercdn.com")
@@ -427,7 +427,7 @@ module SecureHeaders
                   script_src: %w('self')
                 }
               end
-              SecureHeaders.append_content_security_policy_directives(request, {script_src: %w(anothercdn.com)})
+              SecureHeaders.append_content_security_policy_directives(request, { script_src: %w(anothercdn.com) })
 
               hash = SecureHeaders.header_hash_for(request)
               expect(hash["content-security-policy"]).to eq("default-src enforced.com; script-src 'self' anothercdn.com")
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index b0c774d9..65627eec 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -41,18 +41,16 @@ def expect_default_values(hash)
 
 module SecureHeaders
   class Configuration
-    class << self
-      def clear_default_config
-        remove_instance_variable(:@default_config) if defined?(@default_config)
-      end
+    def self.clear_default_config
+      remove_instance_variable(:@default_config) if defined?(@default_config)
+    end
 
-      def clear_overrides
-        remove_instance_variable(:@overrides) if defined?(@overrides)
-      end
+    def self.clear_overrides
+      remove_instance_variable(:@overrides) if defined?(@overrides)
+    end
 
-      def clear_appends
-        remove_instance_variable(:@appends) if defined?(@appends)
-      end
+    def self.clear_appends
+      remove_instance_variable(:@appends) if defined?(@appends)
     end
   end
 end