diff --git a/ci/Jenkinsfile.hermes-agent-image b/ci/Jenkinsfile.hermes-agent-image
index 8a177434..0f459982 100644
--- a/ci/Jenkinsfile.hermes-agent-image
+++ b/ci/Jenkinsfile.hermes-agent-image
@@ -152,8 +152,6 @@ spec:
               ;;
           esac
           test "${#EXPECTED_SOURCE_REVISION}" -eq 40
-          git fetch --no-tags origin main
-          git checkout --detach origin/main
           actual_revision="$(git rev-parse HEAD)"
           test "${actual_revision}" = "$(git rev-parse origin/main)"
           git merge-base --is-ancestor "${EXPECTED_SOURCE_REVISION}" "${actual_revision}"
diff --git a/ci/Jenkinsfile.hermes-webui-image b/ci/Jenkinsfile.hermes-webui-image
index 7e6c45c3..8761cd3d 100644
--- a/ci/Jenkinsfile.hermes-webui-image
+++ b/ci/Jenkinsfile.hermes-webui-image
@@ -152,8 +152,6 @@ spec:
               ;;
           esac
           test "${#EXPECTED_SOURCE_REVISION}" -eq 40
-          git fetch --no-tags origin main
-          git checkout --detach origin/main
           actual_revision="$(git rev-parse HEAD)"
           test "${actual_revision}" = "$(git rev-parse origin/main)"
           git merge-base --is-ancestor "${EXPECTED_SOURCE_REVISION}" "${actual_revision}"
diff --git a/testing/tests/test_hermes_image_builder.py b/testing/tests/test_hermes_image_builder.py
index 63171f1f..f243e485 100644
--- a/testing/tests/test_hermes_image_builder.py
+++ b/testing/tests/test_hermes_image_builder.py
@@ -99,6 +99,8 @@ def test_pipeline_requires_reviewed_main_and_runtime_credentials() -> None:
     assert 'test "${PUBLISH_IMAGE}" = "true"' in source
     assert 'test "${CONFIRM_PUBLISH}" = "PUBLISH HERMES AGENT"' in source
     assert "git rev-parse origin/main" in source
+    assert "git fetch --no-tags origin main" not in source
+    assert 'git merge-base --is-ancestor "${EXPECTED_SOURCE_REVISION}"' in source
     assert "credentialsId: 'harbor-robot'" in source
     assert "set +x" in source
     assert "umask 077" in source
diff --git a/testing/tests/test_hermes_webui_release.py b/testing/tests/test_hermes_webui_release.py
index 20649a40..18259c8d 100644
--- a/testing/tests/test_hermes_webui_release.py
+++ b/testing/tests/test_hermes_webui_release.py
@@ -96,6 +96,7 @@ def test_pipeline_builds_latest_main_containing_reviewed_anchor() -> None:
     source = PIPELINE.read_text(encoding="utf-8")
     assert 'test "${CONFIRM_PUBLISH}" = "PUBLISH HERMES WEBUI"' in source
     assert 'test "${actual_revision}" = "$(git rev-parse origin/main)"' in source
+    assert "git fetch --no-tags origin main" not in source
     assert 'git merge-base --is-ancestor "${EXPECTED_SOURCE_REVISION}"' in source
     assert "dockerfiles/Dockerfile.hermes-webui" in source
     assert "ci/scripts/hermes_webui_release.py" in source