diff --git a/src/Argument.js b/src/Argument.js
new file mode 100644
index 00000000..37cd100d
--- /dev/null
+++ b/src/Argument.js
@@ -0,0 +1,13 @@
+// @flow
+
+export default class Argument {
+  name: string;
+  required: boolean;
+  variadic: boolean;
+
+  constructor(name: string, required: boolean = false, variadic: boolean = false) {
+    this.name = name;
+    this.required = required;
+    this.variadic = variadic;
+  }
+}
diff --git a/src/Command.js b/src/Command.js
index d35c7ec7..ed21f3d5 100755
--- a/src/Command.js
+++ b/src/Command.js
@@ -1,6 +1,7 @@
 // @flow
 
 import EventEmitter from 'events';
+import Argument from './Argument';
 import Option from './Option';
 // import camelCase from './utils/camelCase';
 import humanReadableArgName from './utils/humanReadableArgName';
@@ -9,7 +10,6 @@ import padRow from './utils/padRow';
 
 import type {
   ActionCallback,
-  Argument,
   Autocomplete,
   CancelCallback,
   DoneCallback,
@@ -28,7 +28,7 @@ export default class Command extends EventEmitter {
   options: Option[];
   _allowUnknownOptions: boolean;
   _aliases: string[];
-  _args: Argument[];
+  _args: Argument[]; // TODO - Unprivate
   _autocomplete: ?Autocomplete;
   _cancel: ?CancelCallback;
   _catch: boolean;
@@ -384,7 +384,11 @@ export default class Command extends EventEmitter {
       }
 
       if (argDetails.name) {
-        this._args.push(argDetails);
+        this._args.push(new Argument(
+          argDetails.name,
+          argDetails.required,
+          argDetails.variadic,
+        ));
       }
     });
 
diff --git a/src/types.js b/src/types.js
index aafdba3a..bcd0d15b 100644
--- a/src/types.js
+++ b/src/types.js
@@ -10,12 +10,6 @@ export type ActionCallback = (
   callback: (error: ?Error) => void,
 ) => ?Promise<string>;
 
-export type Argument = {
-  name: string,
-  required: boolean,
-  variadic: boolean,
-};
-
 export type Autocomplete =
   // Array of strings
   string[] |
diff --git a/src/utils/humanReadableArgName.js b/src/utils/humanReadableArgName.js
index 70e19e03..a4fc5bb6 100644
--- a/src/utils/humanReadableArgName.js
+++ b/src/utils/humanReadableArgName.js
@@ -1,6 +1,6 @@
 // @flow
 
-import type { Argument } from '../types';
+import type Argument from '../Argument';
 
 /**
  * Makes an argument name pretty for help.