diff --git a/README.md b/README.md
index 26e7b45..b063a11 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@ $ pip install sphinxcontrib-d2lang
 
 `conf.py`
 
-```conf.py
+```python
 extensions = [
     "sphinxcontrib.d2lang",
 ]