diff --git a/index.d.ts b/index.d.ts
index b7c1df1..6ccd2aa 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,4 +1,12 @@
-import { Task, task, taskGroup } from 'ember-concurrency';
+import {
+  Task,
+  TaskInstance,
+  EncapsulatedTask,
+  EncapsulatedTaskProperty,
+  EncapsulatedTaskState,
+  task,
+  taskGroup,
+} from 'ember-concurrency';
 
 declare module 'ember-concurrency' {
   export type AsyncTaskFunction<T, Args extends any[]> = (...args: Args) => Promise<T>;
@@ -9,21 +17,40 @@ declare module 'ember-concurrency' {
   export type AsyncTaskFunctionReturnType<T extends AsyncTaskFunction<any, any[]>> =
     T extends (...args: any[]) => Promise<infer R> ? R : unknown;
 
+  export type TaskForAsyncTaskFunction<T extends AsyncTaskFunction<any, any[]>> =
+    Task<AsyncTaskFunctionReturnType<T>, AsyncTaskFunctionArgs<T>>;
+
+  export type TaskInstanceForAsyncTaskFunction<T extends AsyncTaskFunction<any, any[]>> =
+    TaskInstance<AsyncTaskFunctionReturnType<T>>;
+
   export interface AsyncEncapsulatedTaskDescriptor<T, Args extends any[]> {
     perform(...args: Args): Promise<T>;
   }
 
   export type AsyncEncapsulatedTaskDescriptorArgs<T extends AsyncEncapsulatedTaskDescriptor<any, any[]>> =
-    T extends (...args: infer A) => Promise<any> ? A : [];
+    T extends { perform(...args: infer A): Promise<any> } ? A : [];
 
   export type AsyncEncapsulatedTaskDescriptorReturnType<T extends AsyncEncapsulatedTaskDescriptor<any, any[]>> =
-    T extends (...args: any[]) => Promise<infer R> ? R : unknown;
+    T extends { perform(...args: any[]): Promise<infer R> } ? R : unknown;
+
+  export type AsyncEncapsulatedTaskState<T extends object> = EncapsulatedTaskState<T>;
+
+  export type TaskForAsyncEncapsulatedTaskDescriptor<T extends AsyncEncapsulatedTaskDescriptor<any, any[]>> =
+    EncapsulatedTask<
+      AsyncEncapsulatedTaskDescriptorReturnType<T>,
+      AsyncEncapsulatedTaskDescriptorArgs<T>,
+      AsyncEncapsulatedTaskState<T>
+    >;
+
+  export type TaskInstanceForAsyncEncapsulatedTaskDescriptor<T extends AsyncEncapsulatedTaskDescriptor<any, any[]>> =
+    TaskInstance<AsyncEncapsulatedTaskDescriptorReturnType<T>> & AsyncEncapsulatedTaskDescriptorArgs<T>;
 
   function task<T extends AsyncTaskFunction<any, any[]>>(taskFn: T):
     TaskProperty<AsyncTaskFunctionReturnType<T>, AsyncTaskFunctionArgs<T>>;
   function task<T extends AsyncEncapsulatedTaskDescriptor<any, any[]>>(taskFn: T):
-    TaskProperty<AsyncEncapsulatedTaskDescriptorReturnType<T>, AsyncEncapsulatedTaskDescriptorArgs<T>>;
-
-  function taskGroup<T extends AsyncTaskFunction<any, any[]>>(taskFn: T):
-    TaskGroup<AsyncTaskFunctionReturnType<T>>;
+    EncapsulatedTaskProperty<
+      AsyncEncapsulatedTaskDescriptorReturnType<T>,
+      AsyncEncapsulatedTaskDescriptorArgs<T>,
+      AsyncEncapsulatedTaskState<T>
+    >;
 }
diff --git a/package.json b/package.json
index de9c54b..d394cf7 100644
--- a/package.json
+++ b/package.json
@@ -30,6 +30,9 @@
     "ember-cli-babel-plugin-helpers": "^1.1.0",
     "ember-cli-htmlbars": "^4.3.1"
   },
+  "peerDependencies": {
+    "ember-concurrency": "^1.2.1"
+  },
   "devDependencies": {
     "@babel/core": "^7.10.2",
     "@babel/plugin-syntax-class-properties": "^7.10.1",
@@ -49,7 +52,7 @@
     "ember-cli-inject-live-reload": "^2.0.2",
     "ember-cli-sri": "^2.1.1",
     "ember-cli-uglify": "^3.0.0",
-    "ember-concurrency": "^1.2.0",
+    "ember-concurrency": "^1.2.1",
     "ember-concurrency-decorators": "^2.0.0",
     "ember-disable-prototype-extensions": "^1.1.3",
     "ember-export-application-global": "^2.0.1",
diff --git a/yarn.lock b/yarn.lock
index dca59fc..94249ff 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -5113,10 +5113,10 @@ ember-concurrency-decorators@^2.0.0:
     ember-cli-htmlbars "^4.3.1"
     ember-cli-typescript "^3.1.4"
 
-ember-concurrency@^1.2.0:
-  version "1.2.0"
-  resolved "https://registry.yarnpkg.com/ember-concurrency/-/ember-concurrency-1.2.0.tgz#f8d09ff035ba7652f01de198b9e16424ef2b8522"
-  integrity sha512-XEKleKlcJQOTbMHEbEtIYF/VXSJDVB8H3pRFY5qmGqGujvpLaJY0GCQ6xtnTDdmSDkBO77FJ9o36GL7iwyqn6g==
+ember-concurrency@^1.2.1:
+  version "1.2.1"
+  resolved "https://registry.yarnpkg.com/ember-concurrency/-/ember-concurrency-1.2.1.tgz#54fb234579638c5c43d4153a4e14567fe2b2e325"
+  integrity sha512-6zlK3BndPPZlSVWq6xBohwobpDKrI58nMMDfD8OqjoeBwnaznuyVHJqDZ46NRJrvSqYX6R96XBBVpDGCCcbK+w==
   dependencies:
     ember-cli-babel "^7.7.3"
     ember-compatibility-helpers "^1.2.0"