diff --git a/tests/hermes_cli/test_web_server.py b/tests/hermes_cli/test_web_server.py
index 9f7a6d810a..025a6cc153 100644
--- a/tests/hermes_cli/test_web_server.py
+++ b/tests/hermes_cli/test_web_server.py
@@ -440,6 +440,9 @@ class TestWebServerEndpoints:
 
         legacy = sqlite3.connect(str(db_path))
         try:
+            # SQLite refuses DROP COLUMN while an index references the
+            # column; a pre-column legacy store has neither.
+            legacy.execute("DROP INDEX IF EXISTS idx_sessions_effective_activity")
             legacy.execute(f"ALTER TABLE sessions DROP COLUMN {missing_column}")
             legacy.commit()
         finally:
@@ -486,6 +489,7 @@ class TestWebServerEndpoints:
 
         legacy = sqlite3.connect(str(db_path))
         try:
+            legacy.execute("DROP INDEX IF EXISTS idx_sessions_effective_activity")
             legacy.execute("ALTER TABLE sessions DROP COLUMN last_activity_at")
             legacy.commit()
         finally: