diff --git a/manual/src/tree_diffing.md b/manual/src/tree_diffing.md
index a3234768f0..5c4c22c92f 100644
--- a/manual/src/tree_diffing.md
+++ b/manual/src/tree_diffing.md
@@ -52,7 +52,7 @@ Algorithm: A* search
 Output: Merged s-expression file
 
 Tristan Hume wrote a tree diffing algorithm during his 2017 internship
-and Jane Street. The source code is not available, but [he has a blog
+at Jane Street. The source code is not available, but [he has a blog
 post](https://thume.ca/2017/06/17/tree-diffing/) discussing the design
 in depth.