diff --git a/internal/storage/backend.go b/internal/storage/backend.go
index 6af0ccd..af0b129 100644
--- a/internal/storage/backend.go
+++ b/internal/storage/backend.go
@@ -226,7 +226,7 @@ func (b *Backend) initializeSchema() error {
 
 	// Migration: Add storage limit fields to users table
 	defaultStorageLimit, _ := b.config.GetDefaultUserStorageLimitBytes()
-	_, err = b.db.Exec(`ALTER TABLE users ADD COLUMN storage_limit INTEGER DEFAULT ?`, defaultStorageLimit)
+	_, err = b.db.Exec(fmt.Sprintf(`ALTER TABLE users ADD COLUMN storage_limit INTEGER DEFAULT %d`, defaultStorageLimit))
 	if err != nil && !isColumnExistsError(err) {
 		return fmt.Errorf("failed to add storage_limit column: %w", err)
 	}