diff --git a/internal/report/snapshots.go b/internal/report/snapshots.go
index 3a04b3c..cfd707c 100644
--- a/internal/report/snapshots.go
+++ b/internal/report/snapshots.go
@@ -809,7 +809,7 @@ func addTotalsChartSheet(logger *slog.Logger, database db.Database, ctx context.
 		if err != nil || len(records) == 0 {
 			return
 		}
-		points, err := buildHourlyTotals(ctx, database.DB(), records)
+		points, err := buildHourlyTotals(ctx, logger, database.DB(), records)
 		if err != nil || len(points) == 0 {
 			return
 		}
@@ -1077,7 +1077,10 @@ type totalsPoint struct {
 	GoldTotal     float64
 }
 
-func buildHourlyTotals(ctx context.Context, dbConn *sqlx.DB, records []SnapshotRecord) ([]totalsPoint, error) {
+func buildHourlyTotals(ctx context.Context, logger *slog.Logger, dbConn *sqlx.DB, records []SnapshotRecord) ([]totalsPoint, error) {
+	if logger == nil {
+		logger = slog.Default()
+	}
 	type hourBucket struct {
 		samples     int
 		vmSum       float64
@@ -1096,13 +1099,13 @@ func buildHourlyTotals(ctx context.Context, dbConn *sqlx.DB, records []SnapshotR
 			return nil, err
 		}
 		if record.SnapshotCount == 0 {
-			slog.Debug("hourly totals skipping empty snapshot", "table", record.TableName, "snapshot_time", record.SnapshotTime)
+			logger.Debug("hourly totals skipping empty snapshot", "table", record.TableName, "snapshot_time", record.SnapshotTime)
 			continue
 		}
 		if record.SnapshotCount < 0 {
 			rowsExist, err := db.TableHasRows(ctx, dbConn, record.TableName)
 			if err != nil {
-				slog.Debug("hourly totals snapshot probe failed", "table", record.TableName, "snapshot_time", record.SnapshotTime, "error", err)
+				logger.Debug("hourly totals snapshot probe failed", "table", record.TableName, "snapshot_time", record.SnapshotTime, "error", err)
 			}
 			if err != nil || !rowsExist {
 				continue
@@ -1193,7 +1196,7 @@ FROM (
 		bronzeAvg := bucket.bronzeSum / denom
 		silverAvg := bucket.silverSum / denom
 		goldAvg := bucket.goldSum / denom
-		slog.Debug(
+		logger.Debug(
 			"hourly totals bucket",
 			"hour_start", time.Unix(key, 0).Local().Format("2006-01-02 15:00"),
 			"samples", bucket.samples,