diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a89354b..b426c66 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -79,7 +79,65 @@ jobs:
           cleanup
 
           docker compose --env-file .env.example up -d db
-          docker compose --env-file .env.example --profile tools run --build --rm migrate
+
+          # One historical production-reset migration intentionally requires the
+          # functional admin account to exist before it runs. On a brand-new CI
+          # database, prove the chain stops at that exact guard, seed only that
+          # historical prerequisite, then continue. The historical migration is
+          # deliberately left untouched.
+          bootstrap_log="$(mktemp)"
+          set +e
+          docker compose --env-file .env.example --profile tools run --build --rm migrate 2>&1 | tee "$bootstrap_log"
+          bootstrap_status=${PIPESTATUS[0]}
+          set -e
+          if [ "$bootstrap_status" -eq 0 ]; then
+            echo "ERROR: clean migration rehearsal unexpectedly passed without the historical admin prerequisite." >&2
+            exit 1
+          fi
+          grep -Fq 'Production reset aborted: expected exactly one username admin, found 0' "$bootstrap_log" || {
+            echo "ERROR: migration rehearsal failed before the expected historical admin guard." >&2
+            exit 1
+          }
+          rm -f "$bootstrap_log"
+
+          docker compose --env-file .env.example exec -T db \
+            psql -v ON_ERROR_STOP=1 -U dhv2_owner -d dhv2 <<'SQL'
+          DO $$
+          DECLARE
+            admin_user_id uuid;
+            admin_role_id uuid;
+          BEGIN
+            SELECT id INTO admin_role_id
+            FROM roles
+            WHERE code = 'admin';
+
+            IF admin_role_id IS NULL THEN
+              RAISE EXCEPTION 'CI bootstrap failed: admin role is missing before production reset';
+            END IF;
+
+            INSERT INTO users (
+              username,
+              password_hash,
+              first_name,
+              last_name,
+              status,
+              must_change_password
+            ) VALUES (
+              'admin',
+              'CI_BOOTSTRAP_ONLY_NOT_A_REAL_PASSWORD_HASH',
+              'CI',
+              'Bootstrap',
+              'ACTIVE',
+              true
+            )
+            RETURNING id INTO admin_user_id;
+
+            INSERT INTO user_roles (user_id, role_id)
+            VALUES (admin_user_id, admin_role_id);
+          END $$;
+          SQL
+
+          docker compose --env-file .env.example --profile tools run --rm migrate
 
           docker compose --env-file .env.example exec -T db \
             psql -v ON_ERROR_STOP=1 -U dhv2_owner -d dhv2 <<'SQL'