diff --git a/src/add-ons/kernel/file_systems/bfs/BlockAllocator.cpp b/src/add-ons/kernel/file_systems/bfs/BlockAllocator.cpp
index 3be1567c9f..8dc8f3f4b0 100644
--- a/src/add-ons/kernel/file_systems/bfs/BlockAllocator.cpp
+++ b/src/add-ons/kernel/file_systems/bfs/BlockAllocator.cpp
@@ -2080,6 +2080,8 @@ BlockAllocator::_AddInodeToIndex(Inode* inode)
 		if (index->inode == NULL)
 			continue;
 
+		index->inode->WriteLockInTransaction(transaction);
+
 		BPlusTree* tree = index->inode->Tree();
 		if (tree == NULL)
 			return B_ERROR;