diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 2b250c610562..2e924f60ea6f 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -6519,9 +6519,10 @@ void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb,
 	char *kaddr;
 
 	assert_eb_page_uptodate(eb, eb->pages[0]);
-	kaddr = page_address(eb->pages[0]) + get_eb_offset_in_page(eb, 0);
-	memcpy(kaddr + offsetof(struct btrfs_header, chunk_tree_uuid), srcv,
-			BTRFS_FSID_SIZE);
+	kaddr = page_address(eb->pages[0]) +
+		get_eb_offset_in_page(eb, offsetof(struct btrfs_header,
+						   chunk_tree_uuid));
+	memcpy(kaddr, srcv, BTRFS_FSID_SIZE);
 }
 
 void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *srcv)
@@ -6529,9 +6530,9 @@ void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *srcv)
 	char *kaddr;
 
 	assert_eb_page_uptodate(eb, eb->pages[0]);
-	kaddr = page_address(eb->pages[0]) + get_eb_offset_in_page(eb, 0);
-	memcpy(kaddr + offsetof(struct btrfs_header, fsid), srcv,
-			BTRFS_FSID_SIZE);
+	kaddr = page_address(eb->pages[0]) +
+		get_eb_offset_in_page(eb, offsetof(struct btrfs_header, fsid));
+	memcpy(kaddr, srcv, BTRFS_FSID_SIZE);
 }
 
 void write_extent_buffer(const struct extent_buffer *eb, const void *srcv,