diff --git a/lib/pact_broker/client/git.rb b/lib/pact_broker/client/git.rb
index e91312cf..f912311b 100644
--- a/lib/pact_broker/client/git.rb
+++ b/lib/pact_broker/client/git.rb
@@ -25,7 +25,7 @@ module Git
       using PactBroker::Client::HashRefinements
 
       COMMAND = 'git rev-parse --abbrev-ref HEAD'.freeze
-      BRANCH_ENV_VAR_NAMES = %w{GITHUB_REF BUILDKITE_BRANCH CIRCLE_BRANCH TRAVIS_BRANCH GIT_BRANCH GIT_LOCAL_BRANCH APPVEYOR_REPO_BRANCH CI_COMMIT_REF_NAME BITBUCKET_BRANCH}.freeze
+      BRANCH_ENV_VAR_NAMES = %w{GITHUB_HEAD_REF GITHUB_REF BUILDKITE_BRANCH CIRCLE_BRANCH TRAVIS_BRANCH GIT_BRANCH GIT_LOCAL_BRANCH APPVEYOR_REPO_BRANCH CI_COMMIT_REF_NAME BITBUCKET_BRANCH}.freeze
       COMMIT_ENV_VAR_NAMES = %w{GITHUB_SHA BUILDKITE_COMMIT CIRCLE_SHA1 TRAVIS_COMMIT GIT_COMMIT APPVEYOR_REPO_COMMIT CI_COMMIT_ID BITBUCKET_COMMIT}
       BUILD_URL_ENV_VAR_NAMES = %w{BUILDKITE_BUILD_URL CIRCLE_BUILD_URL TRAVIS_BUILD_WEB_URL BUILD_URL }