diff --git a/acid.go b/acid.go
index 47db6aa..16322a5 100644
--- a/acid.go
+++ b/acid.go
@@ -1754,6 +1754,8 @@ func dbOpen(path string) error {
 		fallthrough
 	case 2:
 		// The next migration goes here, remember to increment the number below.
+	default:
+		return fmt.Errorf("unsupported database version: %d", version)
 	}
 
 	if _, err = tx.Exec(