diff --git a/src/Applications/Essential/git.md b/src/Applications/Essential/git.md
index 0301fbe..a22a47f 100644
--- a/src/Applications/Essential/git.md
+++ b/src/Applications/Essential/git.md
@@ -70,3 +70,9 @@ Cleanup unnecessary files:
 ```sh
 git gc
 ```
+
+Find common ancestor:
+
+```sh
+git merge-base A B
+```