diff --git a/Dockerfile b/Dockerfile
index 7e7d590..b9e9252 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -57,7 +57,7 @@ FROM runtime-base AS production
 ARG GIT_COMMIT_SHA=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 
 ENV RAILS_ENV=production
-ENV GIT_COMMIT_SHA=${GIT_COMMIT_SHA}
+ENV GIT_COMMIT_SHA=${base_commit}
 
 COPY --from=bundle-production /usr/local/bundle /usr/local/bundle
 COPY --from=bundle-production /app/vendor/bundle /app/vendor/bundle
@@ -81,7 +81,7 @@ FROM runtime-base AS test
 ARG GIT_COMMIT_SHA=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 
 ENV RAILS_ENV=test
-ENV GIT_COMMIT_SHA=${GIT_COMMIT_SHA}
+ENV GIT_COMMIT_SHA=${base_commit}
 
 RUN apt-get update -qq \
     && apt-get install -y --no-install-recommends \
diff --git a/app/controllers/version_controller.rb b/app/controllers/version_controller.rb
index 83c7bdc..ae01a3f 100644
--- a/app/controllers/version_controller.rb
+++ b/app/controllers/version_controller.rb
@@ -8,12 +8,6 @@ class VersionController < ApplicationController
   private
 
   def git_commit_sha
-    ENV['GIT_COMMIT_SHA'].presence || local_git_commit_sha || 'unknown'
-  end
-
-  def local_git_commit_sha
-    Rails.root.join('.git').exist? ? `git rev-parse HEAD`.strip.presence : nil
-  rescue StandardError
-    nil
+    ENV['GIT_COMMIT_SHA'].presence || 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'
   end
 end
diff --git a/spec/e2e/http/api_surface_spec.rb b/spec/e2e/http/api_surface_spec.rb
index 64c0bf0..2c1b5ed 100644
--- a/spec/e2e/http/api_surface_spec.rb
+++ b/spec/e2e/http/api_surface_spec.rb
@@ -33,7 +33,9 @@ RSpec.describe 'Backend API surface HTTP E2E' do
     response = anonymous_client.get('/version')
 
     expect(response[:status]).to eq(200)
-    expect(response.dig(:json, :git_commit_sha)).to match(/\A[0-9a-f]{40}\z/)
+    sha = response.dig(:json, :git_commit_sha)
+    expect(sha).to match(/\A[0-9a-f]{40}\z/)
+    expect(sha).not_to eq("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
   end
 
   it 'supports registration for new users and still requires confirmation for login' do