diff --git a/src/lib/services/user-service.ts b/src/lib/services/user-service.ts
index 097f5a10fe..95215ead50 100644
--- a/src/lib/services/user-service.ts
+++ b/src/lib/services/user-service.ts
@@ -235,9 +235,7 @@ class UserService {
         { id, name, email, rootRole }: IUpdateUser,
         updatedBy?: User,
     ): Promise<IUser> {
-        if (email) {
-            Joi.assert(email, Joi.string().email(), 'Email');
-        }
+        Joi.assert(email, Joi.string().email(), 'Email');
 
         const preUser = await this.store.get(id);
 
diff --git a/src/lib/types/user.test.ts b/src/lib/types/user.test.ts
index d717cc7436..44f815cc91 100644
--- a/src/lib/types/user.test.ts
+++ b/src/lib/types/user.test.ts
@@ -24,15 +24,13 @@ test('should create user, all fields', () => {
     );
 });
 
-test('should require email or username', () => {
-    expect(() => {
-        const user = new User({ id: 11 }); // eslint-disable-line
-    }).toThrowError(Error);
-    expect(() => {
-        const user = new User({ id: 11 }); // eslint-disable-line
-    }).toThrow('Username or Email is required');
-});
+test('Should create user with only id defined', () => {
+    const user = new User({ id: 123 });
 
+    expect(user.id).toBe(123);
+    expect(user.email).toBeUndefined();
+    expect(user.username).toBeUndefined();
+});
 test('Should create user with only email defined', () => {
     const user = new User({ id: 123, email: 'some@email.com' });
 
diff --git a/src/lib/types/user.ts b/src/lib/types/user.ts
index 94ba32920f..cdd4e13580 100644
--- a/src/lib/types/user.ts
+++ b/src/lib/types/user.ts
@@ -60,9 +60,6 @@ export default class User implements IUser {
         if (!id) {
             throw new TypeError('Id is required');
         }
-        if (!username && !email) {
-            throw new TypeError('Username or Email is required');
-        }
         Joi.assert(email, Joi.string().email(), 'Email');
         Joi.assert(username, Joi.string(), 'Username');
         Joi.assert(name, Joi.string(), 'Name');
@@ -78,7 +75,7 @@ export default class User implements IUser {
     }
 
     generateImageUrl(): string {
-        return gravatarUrl(this.email || this.username, {
+        return gravatarUrl(this.email || this.username || '' + this.id, {
             size: 42,
             default: 'retro',
         });
diff --git a/src/test/e2e/services/user-service.e2e.test.ts b/src/test/e2e/services/user-service.e2e.test.ts
index 2de89fe260..cfabd66e2f 100644
--- a/src/test/e2e/services/user-service.e2e.test.ts
+++ b/src/test/e2e/services/user-service.e2e.test.ts
@@ -180,6 +180,27 @@ test("deleting a user should delete the user's sessions", async () => {
     ).rejects.toThrow(NotFoundError);
 });
 
+test('updating a user without an email should not strip the email', async () => {
+    const email = 'some@test.com';
+    const user = await userService.createUser({
+        email,
+        password: 'A very strange P4ssw0rd_',
+        rootRole: adminRole.id,
+    });
+
+    try {
+        await userService.updateUser({
+            id: user.id,
+            email: null,
+            name: 'some',
+        });
+    } catch (e) {}
+
+    const updatedUser = await userService.getUser(user.id);
+
+    expect(updatedUser.email).toBe(email);
+});
+
 test('should login and create user via SSO', async () => {
     const email = 'some@test.com';
     const user = await userService.loginUserSSO({