diff --git a/backend/handlers/scheduling/time_blockers_test.go b/backend/handlers/scheduling/time_blockers_test.go
index b0e483b..41326ee 100644
--- a/backend/handlers/scheduling/time_blockers_test.go
+++ b/backend/handlers/scheduling/time_blockers_test.go
@@ -612,13 +612,13 @@ func TestCleanupOldReservations(t *testing.T) {
 	oldTime := time.Now().Add(-2 * time.Hour).In(ukLocation)
 	_, err = db.DB.Exec(ctx, `
 		INSERT INTO time_blockers (start_time, duration_minutes, description, created_by)
-		VALUES ($1, 60, $2, $3)`, oldTime, fmt.Sprintf("RESERVATION:%s:timestamp-old", oldUserID), oldUserID)
+		VALUES ($1, 60, $2, $3)`, oldTime, fmt.Sprintf("RESERVATION:user:%s:%d", oldUserID, time.Now().UnixNano()), oldUserID)
 	if err != nil {
 		t.Fatalf("failed to create old reservation: %v", err)
 	}
 
 	// Set old created_at to make it eligible for cleanup (> 1 hour old)
-	_, err = db.DB.Exec(ctx, `UPDATE time_blockers SET created_at = $1 WHERE description LIKE 'RESERVATION:%' AND start_time = $2`, time.Now().Add(-2*time.Hour), oldTime)
+	_, err = db.DB.Exec(ctx, `UPDATE time_blockers SET created_at = $1 WHERE description LIKE 'RESERVATION:user:%' AND start_time = $2`, time.Now().Add(-2*time.Hour), oldTime)
 	if err != nil {
 		t.Fatalf("failed to update old reservation created_at: %v", err)
 	}
@@ -627,13 +627,13 @@ func TestCleanupOldReservations(t *testing.T) {
 	recentTime := time.Now().Add(-30 * time.Minute).In(ukLocation)
 	_, err = db.DB.Exec(ctx, `
 		INSERT INTO time_blockers (start_time, duration_minutes, description, created_by)
-		VALUES ($1, 60, $2, $3)`, recentTime, fmt.Sprintf("RESERVATION:%s:timestamp-recent", recentUserID), recentUserID)
+		VALUES ($1, 60, $2, $3)`, recentTime, fmt.Sprintf("RESERVATION:user:%s:%d", recentUserID, time.Now().UnixNano()), recentUserID)
 	if err != nil {
 		t.Fatalf("failed to create recent reservation: %v", err)
 	}
 
 	// Set recent created_at to recent (< 1 hour old) so it's NOT deleted
-	_, err = db.DB.Exec(ctx, `UPDATE time_blockers SET created_at = $1 WHERE description LIKE 'RESERVATION:%' AND start_time = $2`, time.Now().Add(-30*time.Minute), recentTime)
+	_, err = db.DB.Exec(ctx, `UPDATE time_blockers SET created_at = $1 WHERE description LIKE 'RESERVATION:user:%' AND start_time = $2`, time.Now().Add(-30*time.Minute), recentTime)
 	if err != nil {
 		t.Fatalf("failed to update recent reservation created_at: %v", err)
 	}