diff --git a/lodash/lodash-tests.ts b/lodash/lodash-tests.ts
index f9fcdad509..108c76e538 100644
--- a/lodash/lodash-tests.ts
+++ b/lodash/lodash-tests.ts
@@ -5159,10 +5159,25 @@ result = <boolean>_(Array.prototype.push).isNative();
 }
 
 // _.isNull
-result = <boolean>_.isNull(any);
-result = <boolean>_(1).isNull();
-result = <boolean>_<any>([]).isNull();
-result = <boolean>_({}).isNull();
+module TestIsNull {
+    {
+        let result: boolean;
+
+        result = _.isNull(any);
+
+        result = _(1).isNull();
+        result = _<any>([]).isNull();
+        result = _({}).isNull();
+    }
+
+    {
+        let result: _.LoDashExplicitWrapper<boolean>;
+
+        result = _(1).chain().isNull();
+        result = _<any>([]).chain().isNull();
+        result = _({}).chain().isNull();
+    }
+}
 
 // _.isNumber
 result = <boolean>_.isNumber(any);
diff --git a/lodash/lodash.d.ts b/lodash/lodash.d.ts
index 97b82eacf4..845a134591 100644
--- a/lodash/lodash.d.ts
+++ b/lodash/lodash.d.ts
@@ -8995,9 +8995,10 @@ declare module _ {
     interface LoDashStatic {
         /**
          * Checks if value is null.
+         *
          * @param value The value to check.
          * @return Returns true if value is null, else false.
-         **/
+         */
         isNull(value?: any): boolean;
     }
 
@@ -9008,6 +9009,13 @@ declare module _ {
         isNull(): boolean;
     }
 
+    interface LoDashExplicitWrapperBase<T, TWrapper> {
+        /**
+         * see _.isNull
+         */
+        isNull(): LoDashExplicitWrapper<boolean>;
+    }
+
     //_.isNumber
     interface LoDashStatic {
         /**