diff --git a/substrate/client/state-db/src/lib.rs b/substrate/client/state-db/src/lib.rs
index 5e01a0e063..961f641a1a 100644
--- a/substrate/client/state-db/src/lib.rs
+++ b/substrate/client/state-db/src/lib.rs
@@ -134,7 +134,7 @@ pub enum StateDbError {
 	/// Invalid pruning mode specified. Contains expected mode.
 	IncompatiblePruningModes { stored: PruningMode, requested: PruningMode },
 	/// Too many unfinalized sibling blocks inserted.
-	TooManySiblingBlocks,
+	TooManySiblingBlocks { number: u64 },
 	/// Trying to insert existing block.
 	BlockAlreadyExists,
 	/// Invalid metadata
@@ -184,7 +184,8 @@ impl fmt::Debug for StateDbError {
 				"Incompatible pruning modes [stored: {:?}; requested: {:?}]",
 				stored, requested
 			),
-			Self::TooManySiblingBlocks => write!(f, "Too many sibling blocks inserted"),
+			Self::TooManySiblingBlocks { number } =>
+				write!(f, "Too many sibling blocks at #{number} inserted"),
 			Self::BlockAlreadyExists => write!(f, "Block already exists"),
 			Self::Metadata(message) => write!(f, "Invalid metadata: {}", message),
 			Self::BlockUnavailable =>
diff --git a/substrate/client/state-db/src/noncanonical.rs b/substrate/client/state-db/src/noncanonical.rs
index 84ba94c052..b7eec8ab60 100644
--- a/substrate/client/state-db/src/noncanonical.rs
+++ b/substrate/client/state-db/src/noncanonical.rs
@@ -283,7 +283,12 @@ impl<BlockHash: Hash, Key: Hash> NonCanonicalOverlay<BlockHash, Key> {
 		};
 
 		if level.blocks.len() >= MAX_BLOCKS_PER_LEVEL as usize {
-			return Err(StateDbError::TooManySiblingBlocks)
+			trace!(
+				target: "state-db",
+				"Too many sibling blocks at #{number}: {:?}",
+				level.blocks.iter().map(|b| &b.hash).collect::<Vec<_>>()
+			);
+			return Err(StateDbError::TooManySiblingBlocks { number })
 		}
 		if level.blocks.iter().any(|b| b.hash == *hash) {
 			return Err(StateDbError::BlockAlreadyExists)