from:

http://docs.sequelizejs.com/manual/tutorial/models-definition.html

```
// Enable optimistic locking.  When enabled, sequelize will add a version count attribute
// to the model and throw an OptimisticLockingError error when stale instances are saved.
// Set to true or a string with the attribute name you want to use to enable.
```

IDefineOptions: as commented above -`Set to true or a string`.
Model.d.ts: if a user sets the version in IDefineOptions to a string it is probably to free the version field for something else, in that case it should not be forced to a number.

Author: Izik Lisbon

lib/interfaces/IDefineOptions.ts

@@ -4,7 +4,9 @@ export interface IDefineOptions extends DefineOptions<any> {
   modelName?: string;
 
   /**
-   * To enable optimistic locking.
+   * Enable optimistic locking.  When enabled, sequelize will add a version count attribute
+   * to the model and throw an OptimisticLockingError error when stale instances are saved.
+   * Set to true or a string with the attribute name you want to use to enable.
    */
-  version?: boolean;
+  version?: boolean | string;
 }

lib/models/Model.d.ts

@@ -469,7 +469,7 @@ export declare class Model<T> extends Hooks {
   /**
    * version number automatically created by sequelize if table options.version is true
    */
-  version?: number;
+  version?: number|any;
 
   /**
    * Returns true if this instance has not yet been persisted to the database