diff --git a/source/fs/mufs/block.c b/source/fs/mufs/block.c
index ca6f90b..2bc2015 100644
--- a/source/fs/mufs/block.c
+++ b/source/fs/mufs/block.c
@@ -72,6 +72,8 @@ int mufs_alloc_block(struct mufs *fs, uint32_t *found)
 	if ((index = mufs_next_free_block(fs)) == SIZE_MAX)
 		return -1;
 
+	flash_erase(fs->dev, index, 1);
+
 	*found = index;
 
 	return mufs_mark_block(fs, index, 1);
@@ -87,7 +89,5 @@ int mufs_free_block(struct mufs *fs, uint32_t block)
 	if (block < 1 + nbitmap_size)
 		return -1;
 
-	flash_erase(fs->dev, block, 1);
-
 	return mufs_mark_block(fs, block, 0);
 }