diff --git a/README.md b/README.md
index a5e892e3..22dff2a1 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # stactools
 
-> ![WARNING]
+> [!WARNING]
 > This library does not have an active maintainer.
 > If you'd like to help with maintenance, please open an [issue](https://github.com/stac-utils/stactools/issues) saying as much.