diff --git a/triedb/pathdb/journal.go b/triedb/pathdb/journal.go
index efcc3f2549..42eee2b7f8 100644
--- a/triedb/pathdb/journal.go
+++ b/triedb/pathdb/journal.go
@@ -50,7 +50,11 @@ var (
 // - Version 1: storage.Incomplete field is removed
 // - Version 2: add post-modification state values
 // - Version 3: a flag has been added to indicate whether the storage slot key is the raw key or a hash
-const journalVersion uint64 = 3
+// - Version 4: reserved for bintrie flat-state (per-stem layout). Bumping now
+//              discards any v3 journals belonging to a bintrie database so
+//              that the new layout can be introduced cleanly in follow-up
+//              commits without a migration path.
+const journalVersion uint64 = 4
 
 // loadJournal tries to parse the layer journal from the disk.
 func (db *Database) loadJournal(diskRoot common.Hash) (layer, error) {