diff --git a/lodash/lodash-tests.ts b/lodash/lodash-tests.ts
index fe5a8a0578..75185f8984 100644
--- a/lodash/lodash-tests.ts
+++ b/lodash/lodash-tests.ts
@@ -1254,6 +1254,12 @@ result = <boolean>_(1).isRegExp();
 result = <boolean>_<any>([]).isRegExp();
 result = <boolean>_({}).isRegExp();
 
+// _.isString
+result = <boolean>_.isString(any);
+result = <boolean>_(1).isString();
+result = <boolean>_<any>([]).isString();
+result = <boolean>_({}).isString();
+
 // _.isTypedArray
 result = <boolean>_.isTypedArray([]);
 result = <boolean>_([]).isTypedArray();
@@ -1500,8 +1506,6 @@ result = <boolean>_.isPlainObject(new Stooge('moe', 40));
 result = <boolean>_.isPlainObject([1, 2, 3]);
 result = <boolean>_.isPlainObject({ 'name': 'moe', 'age': 40 });
 
-result = <boolean>_.isString('moe');
-
 result = <string[]>_.keys({ 'one': 1, 'two': 2, 'three': 3 });
 result = <string[]>_({ 'one': 1, 'two': 2, 'three': 3 }).keys().value();
 
diff --git a/lodash/lodash.d.ts b/lodash/lodash.d.ts
index cf5717666b..772b6bc32e 100644
--- a/lodash/lodash.d.ts
+++ b/lodash/lodash.d.ts
@@ -6329,6 +6329,23 @@ declare module _ {
         isRegExp(): boolean;
     }
 
+    //_.isString
+    interface LoDashStatic {
+        /**
+         * Checks if value is classified as a String primitive or object.
+         * @param value The value to check.
+         * @return Returns true if value is correctly classified, else false.
+         **/
+        isString(value?: any): boolean;
+    }
+
+    interface LoDashWrapperBase<T, TWrapper> {
+        /**
+         * see _.isString
+         */
+        isString(): boolean;
+    }
+
     //_.isTypedArray
     interface LoDashStatic {
         /**
@@ -7156,16 +7173,6 @@ declare module _ {
         isPlainObject(value?: any): boolean;
     }
 
-    //_.isString
-    interface LoDashStatic {
-        /**
-        * Checks if value is a string.
-        * @param value The value to check.
-        * @return True if the value is a string, else false.
-        **/
-        isString(value?: any): boolean;
-    }
-
     //_.keys
     interface LoDashStatic {
         /**