diff --git a/src/aws/resource.ts b/src/aws/resource.ts
index a5dd74e..76d3547 100644
--- a/src/aws/resource.ts
+++ b/src/aws/resource.ts
@@ -13,4 +13,8 @@ export default class Resource {
 
     return this
   }
+
+  public toJSON():any {
+    throw new Error('override this')
+  }
 }
diff --git a/src/aws/target.ts b/src/aws/target.ts
index ac48cf0..8a519a1 100644
--- a/src/aws/target.ts
+++ b/src/aws/target.ts
@@ -18,7 +18,7 @@ export default class Target extends Resource {
     }
 
     const nameTarget = this.name.target(this.read)
-    const nameRole = this.name.role()
+    const nameRole = this.options.role || this.name.role()
     const nameDimension = this.name.dimension(this.read)
 
     const DependsOn = [ this.options.table, nameRole ].concat(this.dependencies)
diff --git a/src/plugin.ts b/src/plugin.ts
index fb6320a..22402b2 100644
--- a/src/plugin.ts
+++ b/src/plugin.ts
@@ -5,6 +5,8 @@ import * as util from 'util'
 import Policy from './aws/policy'
 import Role from './aws/role'
 import Target from './aws/target'
+import Resource from './aws/resource'
+import { coerceToArray, getFirstKey } from './utils'
 
 const text = {
   CLI_DONE: 'Added DynamoDB Auto Scaling to CloudFormation!',
@@ -12,7 +14,7 @@ const text = {
   CLI_SKIP: 'Skipping DynamoDB Auto Scaling: %s!',
   CLI_START: 'Configure DynamoDB Auto Scaling …',
   INVALID_CONFIGURATION: 'Invalid serverless configuration',
-  NO_AUTOSCALING_CONFIG: 'Not Auto Scaling configuration found',
+  NO_AUTOSCALING_CONFIG: 'No Auto Scaling configuration found',
   ONLY_AWS_SUPPORT: 'Only supported for AWS provicer'
 }
 
@@ -23,6 +25,7 @@ interface Defaults {
 
 class AWSDBAutoScaling {
   public hooks: {}
+  private options: AutoScalingOptions
 
   /**
    * Constructur
@@ -65,7 +68,7 @@ class AWSDBAutoScaling {
     assert(this.serverless.service.provider.name === 'aws', text.ONLY_AWS_SUPPORT)
 
     assert(this.serverless.service.custom, text.NO_AUTOSCALING_CONFIG)
-    assert(this.serverless.service.custom.capacities, text.NO_AUTOSCALING_CONFIG)
+    assert(this.options.capacities, text.NO_AUTOSCALING_CONFIG)
   }
 
   /**
@@ -89,7 +92,7 @@ class AWSDBAutoScaling {
   /**
    * Create CloudFormation resources for table (and optional index)
    */
-  private resources(table: string, index: string, config: Capacity): any[] {
+  private resources(table: string, index: string, config: Capacity): Resource[] {
     const data = this.defaults(config)
 
     const options: Options = {
@@ -97,7 +100,8 @@ class AWSDBAutoScaling {
       region: this.getRegion(),
       service: this.getServiceName(),
       stage: this.getStage(),
-      table
+      table,
+      role: this.options.role
     }
 
     // Start processing configuration
@@ -106,9 +110,10 @@ class AWSDBAutoScaling {
     )
 
     // Add role to manage Auto Scaling policies
-    const resources: any[] = [
-      new Role(options)
-    ]
+    const resources: any[] = []
+    if (!this.options.role) {
+      resources.push(new Role(options))
+    }
 
     // Only add Auto Scaling for read capacity if configuration set is available
     if (!!config.read) {
@@ -137,10 +142,10 @@ class AWSDBAutoScaling {
    * Generate CloudFormation resources for DynamoDB table and indexes
    */
   private generate(table: string, config: Capacity) {
-    let resources: any[] = []
-    let lastRessources: any[] = []
+    let resources: Resource[] = []
+    let lastRessources: string[] = []
 
-    const indexes = this.normalize(config.index)
+    const indexes = coerceToArray(config.index)
     if (!config.indexOnly) {
       indexes.unshift('') // Horrible solution
     }
@@ -148,41 +153,29 @@ class AWSDBAutoScaling {
     indexes.forEach(
       (index: string) => {
         const current = this.resources(table, index, config).map(
-          (resource: any) => resource.setDependencies(lastRessources).toJSON()
+          resource => resource.setDependencies(lastRessources).toJSON()
         )
 
         resources = resources.concat(current)
-        lastRessources = current.map((item: any) => Object.keys(item).pop())
+        lastRessources = current.map(getFirstKey)
       }
     )
 
     return resources
   }
 
-  /**
-   * Check if parameter is defined and return as array if only a string is provided
-   */
-  private normalize(data: string|string[]): string[] {
-    if (data && data.constructor !== Array) {
-      return [ data as string ]
-    }
-
-    return (data as string[] || []).slice(0)
-  }
-
   /**
    * Process the provided configuration
    */
   private process() {
-    this.serverless.service.custom.capacities.filter(
+    const { capacities } = this.options
+    const allResources = this.serverless.service.provider.compiledCloudFormationTemplate.Resources
+    capacities.filter(
       (config: Capacity) => !!config.read || !!config.write
     ).forEach(
-      (config: Capacity) => this.normalize(config.table).forEach(
+      (config: Capacity) => coerceToArray(config.table).forEach(
         (table: string) => this.generate(table, config).forEach(
-          (resource: string) => _.merge(
-            this.serverless.service.provider.compiledCloudFormationTemplate.Resources,
-            resource
-          )
+          (resources: any) => _.merge(allResources, resources)
         )
       )
     )
@@ -190,7 +183,10 @@ class AWSDBAutoScaling {
 
   private beforeDeployResources(): Promise<any> {
     return Promise.resolve().then(
-      () => this.validate()
+      () => {
+        this.options = this.serverless.service.custom['dynamodb-autoscaling']
+        this.validate()
+      }
     ).then(
       () => this.serverless.cli.log(util.format(text.CLI_START))
     ).then(
diff --git a/src/utils.ts b/src/utils.ts
new file mode 100644
index 0000000..66e7e41
--- /dev/null
+++ b/src/utils.ts
@@ -0,0 +1,5 @@
+export const coerceToArray = <T>(data: T|T[]): T[] => {
+  return ([] as T[]).concat(data || [])
+}
+
+export const getFirstKey = (obj: any):string => Object.keys(obj).pop() as string
diff --git a/test/plugin.spec.ts b/test/plugin.spec.ts
index 68bc905..e919813 100644
--- a/test/plugin.spec.ts
+++ b/test/plugin.spec.ts
@@ -1,17 +1,5 @@
 import * as Plugin from '../src/plugin'
 
-describe('Normalize', () => {
-  it('converts everything to an array', () => {
-    const test = new Plugin({ service: { provider: { stage: 'foo' } } })
-
-    expect(test.normalize('test')).toEqual(['test'])
-    expect(test.normalize(['test'])).toEqual(['test'])
-    expect(test.normalize(['test', 'foo'])).toEqual(['test', 'foo'])
-    expect(test.normalize([])).toEqual([])
-    expect(test.normalize()).toEqual([])
-  })
-})
-
 describe('Defaults', () => {
   it('creates object with defaults', () => {
     const config = {
diff --git a/test/utils.spec.ts b/test/utils.spec.ts
new file mode 100644
index 0000000..063c4cb
--- /dev/null
+++ b/test/utils.spec.ts
@@ -0,0 +1,11 @@
+import { coerceToArray } from '../src/utils'
+
+describe('Normalize', () => {
+  it('converts everything to an array', () => {
+    expect(coerceToArray('test')).toEqual(['test'])
+    expect(coerceToArray(['test'])).toEqual(['test'])
+    expect(coerceToArray(['test', 'foo'])).toEqual(['test', 'foo'])
+    expect(coerceToArray([])).toEqual([])
+    expect(coerceToArray()).toEqual([])
+  })
+})
diff --git a/vendor/main.d.ts b/vendor/main.d.ts
index 1a718cf..61263b8 100644
--- a/vendor/main.d.ts
+++ b/vendor/main.d.ts
@@ -4,6 +4,7 @@ declare interface Capacity {
   indexOnly?: boolean
   write?: CapacityConfiguration
   read?: CapacityConfiguration
+  generateRoles?: boolean
 }
 
 declare interface CapacityConfiguration {
@@ -18,6 +19,12 @@ declare interface Options {
   service: string
   stage: string
   table: string
+  role?: string
+}
+
+declare interface AutoScalingOptions {
+  role?: string // external role logical id
+  capacities: Capacity[]
 }
 
 /**
@@ -26,7 +33,7 @@ declare interface Options {
 declare namespace Serverless {
   namespace Service {
     interface Custom {
-      capacities: Capacity[]
+      ['dynamodb-autoscaling']: AutoScalingOptions
     }
   }
-}
\ No newline at end of file
+}