diff --git a/design/XFS_Filesystem_Structure/overview.asciidoc b/design/XFS_Filesystem_Structure/overview.asciidoc
old mode 100644
new mode 100755
index d15b50a..7628a7d
--- a/design/XFS_Filesystem_Structure/overview.asciidoc
+++ b/design/XFS_Filesystem_Structure/overview.asciidoc
@@ -28,7 +28,7 @@
 blocks, which makes sparse files and directories possible.  Directory entries
 and extended attributes are contained inside a second-level data structure
 within the blocks that are mapped by the forks.  This structure consists of
-variable-length directory or attribute records and possible a second B+tree to
+variable-length directory or attribute records and, possibly, a second B+tree to
 index these records.
 
 XFS employs a journalling log in which metadata changes are collected so that