diff --git a/lodash/lodash-tests.ts b/lodash/lodash-tests.ts
index 88661ccb1..b4528be6d 100644
--- a/lodash/lodash-tests.ts
+++ b/lodash/lodash-tests.ts
@@ -5391,20 +5391,33 @@ result = <boolean>_({}).isArray();
 }
 
 // _.isBoolean
-result = <boolean>_.isBoolean(any);
-result = <boolean>_(1).isBoolean();
-result = <boolean>_<any>([]).isBoolean();
-result = <boolean>_({}).isBoolean();
-{
-    let value: number[]|boolean = [1, 3, 5];
-    if (_.isBoolean(value)) {
-        let b: boolean = value;
-        // compile error
-        // let length: number = value.length;
-    } else {
-        let length: number = value.length;
-        // compile error
-        // let b: boolean = value;
+module TestIsBoolean {
+    {
+        let value: number|boolean;
+
+        if (_.isBoolean(value)) {
+            let result: boolean = value;
+        }
+        else {
+            let result: number = value;
+        }
+    }
+
+    {
+        let result: boolean;
+
+        result = _.isBoolean(any);
+        result = _(1).isBoolean();
+        result = _<any>([]).isBoolean();
+        result = _({}).isBoolean();
+    }
+
+    {
+        let result: _.LoDashExplicitWrapper<boolean>;
+
+        result = _(1).chain().isBoolean();
+        result = _<any>([]).chain().isBoolean();
+        result = _({}).chain().isBoolean();
     }
 }
 
diff --git a/lodash/lodash.d.ts b/lodash/lodash.d.ts
index 0663a68fc..f44d3f63f 100644
--- a/lodash/lodash.d.ts
+++ b/lodash/lodash.d.ts
@@ -9244,9 +9244,10 @@ declare module _ {
     interface LoDashStatic {
         /**
          * Checks if value is classified as a boolean primitive or object.
+         *
          * @param value The value to check.
          * @return Returns true if value is correctly classified, else false.
-         **/
+         */
         isBoolean(value?: any): value is boolean;
     }
 
@@ -9257,6 +9258,13 @@ declare module _ {
         isBoolean(): boolean;
     }
 
+    interface LoDashExplicitWrapperBase<T, TWrapper> {
+        /**
+         * @see _.isBoolean
+         */
+        isBoolean(): LoDashExplicitWrapper<boolean>;
+    }
+
     //_.isDate
     interface LoDashStatic {
         /**