diff --git a/eth/api_debug.go b/eth/api_debug.go
index 22dd6b0cf7..dc9f568146 100644
--- a/eth/api_debug.go
+++ b/eth/api_debug.go
@@ -362,6 +362,9 @@ func (api *DebugAPI) getModifiedAccounts(startBlock, endBlock *types.Block) ([]c
 // The (from, to) parameters are the sequence of blocks to search, which can go
 // either forwards or backwards
 func (api *DebugAPI) GetAccessibleState(from, to rpc.BlockNumber) (uint64, error) {
+	if api.eth.blockchain.TrieDB().Scheme() == rawdb.PathScheme {
+		return 0, errors.New("state history is not yet available in path-based scheme")
+	}
 	db := api.eth.ChainDb()
 	var pivot uint64
 	if p := rawdb.ReadLastPivotNumber(db); p != nil {
@@ -422,6 +425,9 @@ func (api *DebugAPI) GetAccessibleState(from, to rpc.BlockNumber) (uint64, error
 // If the value is shorter than the block generation time, or even 0 or negative,
 // the node will flush trie after processing each block (effectively archive mode).
 func (api *DebugAPI) SetTrieFlushInterval(interval string) error {
+	if api.eth.blockchain.TrieDB().Scheme() == rawdb.PathScheme {
+		return errors.New("trie flush interval is undefined for path-based scheme")
+	}
 	t, err := time.ParseDuration(interval)
 	if err != nil {
 		return err
@@ -431,6 +437,9 @@ func (api *DebugAPI) SetTrieFlushInterval(interval string) error {
 }
 
 // GetTrieFlushInterval gets the current value of in-memory trie flush interval
-func (api *DebugAPI) GetTrieFlushInterval() string {
-	return api.eth.blockchain.GetTrieFlushInterval().String()
+func (api *DebugAPI) GetTrieFlushInterval() (string, error) {
+	if api.eth.blockchain.TrieDB().Scheme() == rawdb.PathScheme {
+		return "", errors.New("trie flush interval is undefined for path-based scheme")
+	}
+	return api.eth.blockchain.GetTrieFlushInterval().String(), nil
 }