diff --git a/.tool-versions b/.tool-versions
index e910ebe5..a5bf4812 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1,4 +1,4 @@
-nodejs 18.18.2 # Keep in sync with package.json.
+nodejs 20.9.0 # Keep in sync with package.json.
 yarn 1.22.19
 python 3.12.0 # Keep in sync with .pre-commit-config.yaml and pyproject.toml.
 poetry 1.6.1
diff --git a/package.json b/package.json
index b0dff5e8..56149170 100644
--- a/package.json
+++ b/package.json
@@ -16,7 +16,7 @@
     "test": "yarn run tsc && yarn run jest:esm"
   },
   "engines": {
-    "node": "18.18.2",
+    "node": "20.9.0",
     "yarn": "3.6.4"
   },
   "packageManager": "yarn@3.6.4",