diff --git a/node-ffi/node-ffi-tests.ts b/node-ffi/node-ffi-tests.ts
index a29d8dbd6d..06aa2a2ee7 100644
--- a/node-ffi/node-ffi-tests.ts
+++ b/node-ffi/node-ffi-tests.ts
@@ -2,6 +2,7 @@
 
 import ffi = require('ffi');
 import ref = require('ref');
+import Struct = require('ref-struct');
 
 {
     var sqlite3 = ref.types.void;
@@ -54,3 +55,25 @@ import ref = require('ref');
     var buf = ref.alloc('int64');
     ref.writeInt64LE(buf, 0, '9223372036854775807');
 }
+{
+    var S1 = Struct({ a: ref.types.int });
+    var S2 = new Struct({ a: 'int' });
+}
+{
+    var P = new Struct;
+    P.defineProperty('a', ref.types.int);
+    P.defineProperty('d', 'long');
+}
+{
+    var SimpleStruct = Struct({
+        first : ref.types.byte,
+        last  : ref.types.byte
+    });
+
+    var ss = new SimpleStruct({ first: 50, last: 100 });
+    ss.first += 200;
+}
+{
+    var ST = Struct();
+    var test: ffi.Type = ST.fields['t'].type;
+}
diff --git a/node-ffi/node-ffi.d.ts b/node-ffi/node-ffi.d.ts
index 9b4987a427..2ec08e8131 100644
--- a/node-ffi/node-ffi.d.ts
+++ b/node-ffi/node-ffi.d.ts
@@ -6,9 +6,7 @@
 /// <reference path="../node/node.d.ts" />
 
 declare module "ffi" {
-    // import StructType = require('ref-struct');
-    
-    export interface StructType {}
+    import StructType = require('ref-struct');
 
     export interface Type {
         /** The size in bytes required to hold this datatype. */
@@ -435,3 +433,60 @@ interface NodeBuffer {
      */
     inspect(): string;
 }
+
+declare module "ref-struct" {
+    import ffi = require('ffi');
+
+    /**
+     * This is the `constructor` of the Struct type that gets returned.
+     *
+     * Invoke it with `new` to create a new Buffer instance backing the struct.
+     * Pass it an existing Buffer instance to use that as the backing buffer.
+     * Pass in an Object containing the struct fields to auto-populate the
+     * struct with the data.
+     *
+     * @constructor
+     */
+    interface StructType extends ffi.Type {
+        /** Pass it an existing Buffer instance to use that as the backing buffer. */
+        new (arg: NodeBuffer, data?: {}): any;
+        new (data?: {}): any;
+        /** Pass it an existing Buffer instance to use that as the backing buffer. */
+        (arg: NodeBuffer, data?: {}): any;
+        (data?: {}): any;
+
+        fields: {[key: string]: {type: ffi.Type}};
+
+        /**
+         * Adds a new field to the struct instance with the given name and type.
+         * Note that this function will throw an Error if any instances of the struct
+         * type have already been created, therefore this function must be called at the
+         * beginning, before any instances are created.
+         */
+        defineProperty(name: string, type: ffi.Type): void;
+        
+        /**
+         * Adds a new field to the struct instance with the given name and type.
+         * Note that this function will throw an Error if any instances of the struct
+         * type have already been created, therefore this function must be called at the
+         * beginning, before any instances are created.
+         */
+        defineProperty(name: string, type: string): void;
+
+        /**
+         * Custom for struct type instances.
+         * @override
+         */
+        toString(): string;
+    }
+
+    /** The struct type meta-constructor. */
+    var StructType: {
+        new (fields?: {}): StructType;
+        new (fields?: any[]): StructType;
+        (fields?: {}): StructType;
+        (fields?: any[]): StructType;
+    }
+
+    export = StructType;
+}