diff --git a/UPGRADING.md b/UPGRADING.md
index 73d7eb9..b8d5870 100644
--- a/UPGRADING.md
+++ b/UPGRADING.md
@@ -1,3 +1,7 @@
+## 2.1.0
+
+- Add support for `diff` language
+
 ## 2.0.4
 
 - Fix for overflowing highlight tags
diff --git a/tests/targets/test.md b/tests/targets/test.md
index c1e3a79..1d814a0 100644
--- a/tests/targets/test.md
+++ b/tests/targets/test.md
@@ -1,3 +1,4 @@
-```
-{~class~} Foo {}
+```diff
++class Foo {}
+-class Foo {}
 ```
\ No newline at end of file