diff --git a/.circleci/config.yml b/.circleci/config.yml
index 23fcf9e1..9ad5d45b 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -1,35 +1,91 @@
-version: 2
+version: 2.1
 jobs:
-  "Test against Ruby 2.4":
+  test-ruby-2-4:
     docker:
       - image: circleci/ruby:2.4.9
     working_directory: ~/intercom-ruby
     steps:
       - checkout
+      - run:
+          name: Route Bundler through the Socket Firewall registry
+          command: |
+            set -euo pipefail
+            if [ -z "${SOCKET_GEM_URL:-}" ]; then
+              # CircleCI does not share context credentials with forked PRs, so a
+              # fork cannot be routed. Say so rather than failing the contributor.
+              if [ -n "${CIRCLE_PR_REPONAME:-}" ]; then
+                echo "Forked PR: no Socket Firewall credentials available, gems will come from rubygems.org."
+                exit 0
+              fi
+              echo "FATAL: SOCKET_GEM_URL is required (provided by the socket-firewall context)"
+              exit 1
+            fi
+            # Legacy two-argument form: these images ship Bundler 1.x, where
+            # `bundle config set --global` does not exist and silently no-ops.
+            bundle config mirror.https://rubygems.org "$SOCKET_GEM_URL"
+            bundle config mirror.https://rubygems.org | grep -q socket-firewall-registry \
+              || { echo "FAIL: bundler mirror not pointing at Socket Firewall"; exit 1; }
       - run: bundle install
       - run: bundle exec rake
-  "Test against Ruby 2.5":
+  test-ruby-2-5:
     docker:
       - image: circleci/ruby:2.5.7
     working_directory: ~/intercom-ruby
     steps:
       - checkout
+      - run:
+          name: Route Bundler through the Socket Firewall registry
+          command: |
+            set -euo pipefail
+            if [ -z "${SOCKET_GEM_URL:-}" ]; then
+              if [ -n "${CIRCLE_PR_REPONAME:-}" ]; then
+                echo "Forked PR: no Socket Firewall credentials available, gems will come from rubygems.org."
+                exit 0
+              fi
+              echo "FATAL: SOCKET_GEM_URL is required (provided by the socket-firewall context)"
+              exit 1
+            fi
+            bundle config mirror.https://rubygems.org "$SOCKET_GEM_URL"
+            bundle config mirror.https://rubygems.org | grep -q socket-firewall-registry \
+              || { echo "FAIL: bundler mirror not pointing at Socket Firewall"; exit 1; }
       - run: bundle install
       - run: bundle exec rake
-  "Test against Ruby 2.6":
+  test-ruby-2-6:
     docker:
       - image: circleci/ruby:2.6.5
     working_directory: ~/intercom-ruby
     steps:
       - checkout
+      - run:
+          name: Route Bundler through the Socket Firewall registry
+          command: |
+            set -euo pipefail
+            if [ -z "${SOCKET_GEM_URL:-}" ]; then
+              if [ -n "${CIRCLE_PR_REPONAME:-}" ]; then
+                echo "Forked PR: no Socket Firewall credentials available, gems will come from rubygems.org."
+                exit 0
+              fi
+              echo "FATAL: SOCKET_GEM_URL is required (provided by the socket-firewall context)"
+              exit 1
+            fi
+            bundle config mirror.https://rubygems.org "$SOCKET_GEM_URL"
+            bundle config mirror.https://rubygems.org | grep -q socket-firewall-registry \
+              || { echo "FAIL: bundler mirror not pointing at Socket Firewall"; exit 1; }
       - run: bundle install
       - run: bundle exec rake
 
 workflows:
-  version: 2
   build_and_test:
     jobs:
-      - "Test against Ruby 2.4"
-      - "Test against Ruby 2.5"
-      - "Test against Ruby 2.6"
-
+      - test-ruby-2-4:
+          name: "Test against Ruby 2.4"
+          context:
+            - socket-firewall
+      - test-ruby-2-5:
+          name: "Test against Ruby 2.5"
+          context:
+            - socket-firewall
+      - test-ruby-2-6:
+          name: "Test against Ruby 2.6"
+          context:
+            - socket-firewall
diff --git a/Gemfile b/Gemfile
index 4516ffc0..0cfe52d3 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,4 @@
-source "http://rubygems.org"
+source "https://rubygems.org"
 
 gem 'webmock'
 gemspec
diff --git a/changes.txt b/changes.txt
index cac520a9..a881bab0 100644
--- a/changes.txt
+++ b/changes.txt
@@ -1,4 +1,7 @@
-4.2.1
+4.2.3
+- Fixed SyntaxError when reading articles with hyphenated locales
+
+4.2.2
 - Fixed FlatStore to skip hash values when building API request payloads
 - Removed hash validation on FlatStore reads to allow for custom objects
 
diff --git a/lib/intercom/lib/dynamic_accessors.rb b/lib/intercom/lib/dynamic_accessors.rb
index 9d26b4fc..70543397 100644
--- a/lib/intercom/lib/dynamic_accessors.rb
+++ b/lib/intercom/lib/dynamic_accessors.rb
@@ -17,39 +17,46 @@ def define_accessors(attribute, value, object)
         private
 
         def define_flat_store_based_accessors(attribute, value, object)
-          object.instance_eval %Q"
-            def #{attribute}=(value)
-              mark_field_as_changed!(:#{attribute})
-              @#{attribute} = Intercom::Lib::FlatStore.new(value)
+          ivar = ivar_name(attribute, object)
+          object.singleton_class.class_eval do
+            define_method("#{attribute}=") do |val|
+              mark_field_as_changed!(attribute.to_sym)
+              instance_variable_set(ivar, Intercom::Lib::FlatStore.new(val))
             end
-            def #{attribute}
-              @#{attribute}
-            end
-          "
+            define_method(attribute) { instance_variable_get(ivar) }
+          end
         end
 
         def define_date_based_accessors(attribute, value, object)
-          object.instance_eval %Q"
-            def #{attribute}=(value)
-              mark_field_as_changed!(:#{attribute})
-              @#{attribute} = value.nil? ? nil : value.to_i
+          ivar = ivar_name(attribute, object)
+          object.singleton_class.class_eval do
+            define_method("#{attribute}=") do |val|
+              mark_field_as_changed!(attribute.to_sym)
+              instance_variable_set(ivar, val.nil? ? nil : val.to_i)
             end
-            def #{attribute}
-              @#{attribute}.nil? ? nil : Time.at(@#{attribute})
+            define_method(attribute) do
+              time = instance_variable_get(ivar)
+              time.nil? ? nil : Time.at(time)
             end
-          "
+          end
         end
 
         def define_standard_accessors(attribute, value, object)
-            object.instance_eval %Q"
-              def #{attribute}=(value)
-                mark_field_as_changed!(:#{attribute})
-                @#{attribute} = value
-              end
-              def #{attribute}
-                @#{attribute}
-              end
-            "
+          ivar = ivar_name(attribute, object)
+          object.singleton_class.class_eval do
+            define_method("#{attribute}=") do |val|
+              mark_field_as_changed!(attribute.to_sym)
+              instance_variable_set(ivar, val)
+            end
+            define_method(attribute) { instance_variable_get(ivar) }
+          end
+        end
+
+        # Keys such as "pt-BR" are not valid identifiers, so normalise them for the ivar name.
+        def ivar_name(attribute, object)
+          ivar = "@#{attribute.to_s.gsub(/\W/, '_')}"
+          object.register_attribute_key(ivar, attribute) if ivar != "@#{attribute}"
+          ivar
         end
 
       end
diff --git a/lib/intercom/traits/api_resource.rb b/lib/intercom/traits/api_resource.rb
index 8749c196..7a27b399 100644
--- a/lib/intercom/traits/api_resource.rb
+++ b/lib/intercom/traits/api_resource.rb
@@ -37,7 +37,7 @@ def from_hash(hash)
 
       def to_hash
         instance_variables_excluding_dirty_tracking_field.each_with_object({}) do |variable, hash|
-          hash[variable.to_s.delete('@')] = instance_variable_get(variable)
+          hash[attribute_key(variable)] = instance_variable_get(variable)
         end
       end
 
@@ -46,10 +46,18 @@ def to_json(*args)
           next if variable == :@client
 
           value = instance_variable_get(variable)
-          hash[variable.to_s.delete('@')] = value.respond_to?(:to_json) ? value.to_json(*args) : value
+          hash[attribute_key(variable)] = value.respond_to?(:to_json) ? value.to_json(*args) : value
         end
       end
 
+      def register_attribute_key(ivar, attribute)
+        (@attribute_keys ||= {})[ivar.to_sym] = attribute.to_s
+      end
+
+      def attribute_key(variable)
+        (@attribute_keys || {}).fetch(variable, variable.to_s.delete('@'))
+      end
+
       def to_submittable_hash
         submittable_hash = {}
         to_hash.each do |attribute, value|
diff --git a/lib/intercom/traits/dirty_tracking.rb b/lib/intercom/traits/dirty_tracking.rb
index d155c2d9..baad8508 100644
--- a/lib/intercom/traits/dirty_tracking.rb
+++ b/lib/intercom/traits/dirty_tracking.rb
@@ -22,7 +22,7 @@ def mark_field_as_changed!(field_name)
 
       def field_changed?(field_name)
         @changed_fields ||= Set.new
-        field = instance_variable_get("@#{field_name}")
+        field = instance_variable_get("@#{field_name.to_s.gsub(/\W/, '_')}")
         if field.respond_to?(:field_changed?)
           field.to_hash.any? do |attribute, _|
             field.field_changed?(attribute)
@@ -33,7 +33,7 @@ def field_changed?(field_name)
       end
 
       def instance_variables_excluding_dirty_tracking_field
-        instance_variables.reject{|var| var == :@changed_fields}
+        instance_variables.reject{|var| var == :@changed_fields || var == :@attribute_keys}
       end
     end
   end
diff --git a/lib/intercom/version.rb b/lib/intercom/version.rb
index 8e27d974..a5795aa0 100644
--- a/lib/intercom/version.rb
+++ b/lib/intercom/version.rb
@@ -1,3 +1,3 @@
 module Intercom #:nodoc:
-  VERSION = "4.2.1"
+  VERSION = "4.2.3"
 end
diff --git a/spec/unit/intercom/article_spec.rb b/spec/unit/intercom/article_spec.rb
index 9fa3a695..67007ee7 100644
--- a/spec/unit/intercom/article_spec.rb
+++ b/spec/unit/intercom/article_spec.rb
@@ -37,4 +37,22 @@
       client.articles.delete(article)
     end
   end
-end
\ No newline at end of file
+
+  describe "Parsing an Article" do
+    it "handles hyphenated locale keys in translated content" do
+      article = Intercom::Article.from_api(
+        "id" => "1",
+        "type" => "article",
+        "translated_content" => {
+          "type" => "article_translated_content",
+          "fr" => { "type" => "article_content", "title" => "Bonjour" },
+          "pt-BR" => { "type" => "article_content", "title" => "Ola" }
+        }
+      )
+      _(article.translated_content.fr.title).must_equal "Bonjour"
+      _(article.translated_content.public_send("pt-BR").title).must_equal "Ola"
+      article.translated_content.public_send("pt-BR").title = "Oi"
+      _(article.to_submittable_hash).must_equal("translated_content" => { "pt-BR" => { "title" => "Oi" } })
+    end
+  end
+end