diff --git a/types/chai/chai-tests.ts b/types/chai/chai-tests.ts
index 141c985dd4..1614f7e77b 100644
--- a/types/chai/chai-tests.ts
+++ b/types/chai/chai-tests.ts
@@ -887,7 +887,7 @@ function use() {
         _chai.can.use.any();
     });
 
-    let expect = chai
+    const expect = chai
         .use((_chai, util) => {})
         .use((_chai, util) => {})
         .expect;
diff --git a/types/chai/tslint.json b/types/chai/tslint.json
index 022342e522..e3c7a3ed0a 100644
--- a/types/chai/tslint.json
+++ b/types/chai/tslint.json
@@ -9,7 +9,6 @@
         "no-empty-interface": false,
         "no-inferrable-types": false,
         "no-redundant-jsdoc-2": false,
-        "no-unnecessary-generics": false,
-        "prefer-const": false
+        "no-unnecessary-generics": false
     }
 }