diff --git a/worker/tests/conftest.py b/worker/tests/conftest.py
index 1b1a662..42d9594 100644
--- a/worker/tests/conftest.py
+++ b/worker/tests/conftest.py
@@ -8,6 +8,11 @@ import pytest
 def conn():
     dsn = os.environ["DATABASE_URL"]
     connection = psycopg.connect(dsn)
+    # Clean up any pre-existing rows before the test runs (Job cascades from Request).
+    with connection.cursor() as cur:
+        cur.execute('DELETE FROM "Job"')
+        cur.execute('DELETE FROM "Request"')
+    connection.commit()
     yield connection
     # Clean up rows created during the test (Job cascades from Request).
     with connection.cursor() as cur: