diff --git a/types/meteor-astronomy/index.d.ts b/types/meteor-astronomy/index.d.ts
index 2bef7e728c..c17c1d1498 100644
--- a/types/meteor-astronomy/index.d.ts
+++ b/types/meteor-astronomy/index.d.ts
@@ -7,6 +7,11 @@
 /// <reference types="meteor" />
 
 declare namespace MeteorAstronomy {
+    type NonFunctionPropertyNames<T> = { [K in keyof T]: T[K] extends Function ? never : K }[keyof T]; // tslint:disable-line:ban-types
+    type NonFunctionProperties<T> = Pick<T, NonFunctionPropertyNames<T>>;
+    type FunctionPropertyNames<T> = { [K in keyof T]: T[K] extends Function ? K : never }[keyof T]; // tslint:disable-line:ban-types
+    type FunctionProperties<T> = Pick<T, FunctionPropertyNames<T>>;
+
     type TypeOptionsPrimitives = typeof String | typeof Date | typeof Boolean | typeof Object | typeof Number;
     type TypeOptions = TypeOptionsPrimitives | TypeOptionsPrimitives[] | Class<any> | Enum<any>;
     type MongoQuery = object | string;
@@ -40,7 +45,11 @@ declare namespace MeteorAstronomy {
     type ModelField<Field, Doc> = ModelFullField<Field, Doc> | TypeOptions;
 
     type Fields<T> = {
-        [P in keyof T]: ModelField<T[P], T>;
+        [P in keyof NonFunctionProperties<T>]: ModelField<T[P], T>;
+    };
+
+    type Helpers<T> = {
+        [P in keyof FunctionProperties<T>]: (this: T, ...args: any[]) => any;
     };
 
     interface ClassModel<T> {
@@ -53,7 +62,7 @@ declare namespace MeteorAstronomy {
             update: boolean,
             remove: boolean,
         } | boolean;
-        helpers?: object;
+        helpers?: Helpers<T>;
         events?: object;
         meteorMethods?: object;
         indexes?: object;
@@ -61,7 +70,7 @@ declare namespace MeteorAstronomy {
 
     interface EnumModel<T> {
         name: string;
-        identifiers: T[] | object;
+        identifiers: string[] | T;
     }
 
     type Model<T> = T & {
@@ -92,10 +101,10 @@ declare namespace MeteorAstronomy {
         update(search: object | string, query: object, callback?: () => void): void;
     }
 
-    interface Enum<T> {
+    type Enum<T> = T & {
         getValues(): any[];
-        getIdentifier(identifier: T): any;
-    }
+        getIdentifier(identifier: any): string;
+    };
 }
 
 declare module 'meteor/jagi:astronomy' { // tslint:disable-line:no-single-declare-module
diff --git a/types/meteor-astronomy/meteor-astronomy-tests.ts b/types/meteor-astronomy/meteor-astronomy-tests.ts
index 871c02964b..59f0f99644 100644
--- a/types/meteor-astronomy/meteor-astronomy-tests.ts
+++ b/types/meteor-astronomy/meteor-astronomy-tests.ts
@@ -65,8 +65,11 @@ const UserProfile = Class.create<UserProfileInterface>({
 
 interface UserInterface extends Meteor.User {
     address: object;
+    firstName: string;
+    lastName: string;
     phone: string;
     phoneNumber: string;
+    fullName: (param: string) => string;
 }
 
 const User = Class.create<UserInterface>({
@@ -74,9 +77,11 @@ const User = Class.create<UserInterface>({
     collection: Meteor.users as Mongo.Collection<UserInterface>,
     fields: {
         createdAt: Number,
+        firstName: String,
+        lastName: String,
         emails: {
             type: [Object],
-            default: () => [],
+            default: (): Meteor.UserEmail[] => [],
         },
         profile: {
             type: UserProfile,
@@ -91,10 +96,23 @@ const User = Class.create<UserInterface>({
         },
         phone: {
             type: String,
-            resolve(doc) {
+            resolve(doc: UserInterface) {
                 return doc.phoneNumber;
+            },
+        },
+    },
+    helpers: {
+        fullName(param: string): string {
+            const fullName = `${this.firstName} ${this.lastName}`;
+
+            if (param === 'lower') {
+                return fullName.toLowerCase();
+            } else if (param === 'upper') {
+                return fullName.toUpperCase();
             }
-        }
+
+            return fullName;
+        },
     },
     indexes: {
         fullName: { // Index name.
@@ -111,13 +129,16 @@ const user = User.findOne();
 user.set({username: 'user1'});
 user.save();
 
-enum IStatus {
-    OPENED, CLOSED, DONE, CANCELED
+interface StatusInterface {
+    OPENED: number;
+    CLOSED: number;
+    DONE: number;
+    CANCELED: number;
 }
 
-const Status = Enum.create<IStatus>({
+const Status = Enum.create<StatusInterface>({
     name: 'Status',
-    identifiers: IStatus,
+    identifiers: ['OPENED', 'CLOSED', 'DONE', 'CANCELED'],
 });
 
 const Issue = Class.create({
@@ -131,18 +152,25 @@ const Issue = Class.create({
 
 Status.getValues(); // [0, 1, 2, 3]
 
-const StatusBis = Enum.create({
+interface StatusBisInterface {
+    OPENED: string;
+    CLOSED: string;
+    DONE: string;
+    CANCELED: string;
+}
+
+const StatusBis = Enum.create<StatusBisInterface>({
     name: 'Status',
     identifiers: {
-        OPENED: 5,
-        CLOSED: null,
-        DONE: 15,
-        CANCELED: undefined
+        OPENED: 'OPENED',
+        CLOSED: 'CLOSED',
+        DONE: 'DONE',
+        CANCELED: 'CANCELED',
     }
 });
 
 StatusBis.getValues(); // [5, 6, 15, 16]
 
-const statusNumber = IStatus.OPENED;
+const statusNumber = Status.OPENED;
 
 Status.getIdentifier(statusNumber); // "OPENED"