diff --git a/RELEASING.md b/RELEASING.md
index 213f3218..9ebfa098 100644
--- a/RELEASING.md
+++ b/RELEASING.md
@@ -1,6 +1,6 @@
 # Releasing the Polar2Grid Python Package
 
-1. Update setup.py with the new version.
+1. Update pyproject.toml with the new version.
 2. Create a git tag for the new version:
 
    ```bash