diff --git a/eslint.config.js b/eslint.config.js
index c634d89eb..3639ae8ff 100644
--- a/eslint.config.js
+++ b/eslint.config.js
@@ -326,7 +326,6 @@ const configs = [
       "unicorn/no-declarations-before-early-exit": "off",
       "unicorn/no-negated-comparison": "off",
       "unicorn/prefer-early-return": "off",
-      "unicorn/prefer-number-is-safe-integer": "off",
       "unicorn/no-undeclared-class-members": "off",
       "unicorn/no-useless-boolean-cast": "off",
       "unicorn/no-useless-fallback-in-spread": "off",
diff --git a/scripts/prepare-test-for-legacy-nodejs.js b/scripts/prepare-test-for-legacy-nodejs.js
index 961aac7c3..da4e27a2f 100644
--- a/scripts/prepare-test-for-legacy-nodejs.js
+++ b/scripts/prepare-test-for-legacy-nodejs.js
@@ -6,7 +6,7 @@ const packageJson = JSON.parse(fs.readFileSync(packageJsonFile));
 const argv = process.argv.slice(2);
 const nodeVersion = Number(argv[1]);
 
-if (argv[0] !== "--node-version" || !Number.isInteger(nodeVersion)) {
+if (argv[0] !== "--node-version" || !Number.isSafeInteger(nodeVersion)) {
   throw new Error("Expect `--node-version` argument.");
 }
 
diff --git a/src/language-handlebars/parser-glimmer.js b/src/language-handlebars/parser-glimmer.js
index 0ab852dac..956855d5b 100644
--- a/src/language-handlebars/parser-glimmer.js
+++ b/src/language-handlebars/parser-glimmer.js
@@ -34,7 +34,7 @@ function addBackslash(node) {
   }
 }
 
-const isIndex = (value) => Number.isInteger(value) && value >= 0;
+const isIndex = (value) => Number.isSafeInteger(value) && value >= 0;
 // Add `offset` to `loc.{start,end}`
 const setOffset = (node) => {
   const { start, end } = node.loc;
diff --git a/src/language-js/location/is-index.js b/src/language-js/location/is-index.js
index 9ef06cd0e..36386c188 100644
--- a/src/language-js/location/is-index.js
+++ b/src/language-js/location/is-index.js
@@ -1,3 +1,3 @@
-const isIndex = (value) => Number.isInteger(value) && value >= 0;
+const isIndex = (value) => Number.isSafeInteger(value) && value >= 0;
 
 export { isIndex };