diff --git a/src/lib/types/user.ts b/src/lib/types/user.ts
index 8e1509b14c..290eb31db0 100644
--- a/src/lib/types/user.ts
+++ b/src/lib/types/user.ts
@@ -1,5 +1,5 @@
-import gravatarUrl from 'gravatar-url';
 import Joi from 'joi';
+import { generateImageUrl } from '../util/generateImageUrl';
 
 export interface UserData {
     id: number;
@@ -79,10 +79,7 @@ export default class User implements IUser {
     }
 
     generateImageUrl(): string {
-        return gravatarUrl(this.email || this.username || '' + this.id, {
-            size: 42,
-            default: 'retro',
-        });
+        return generateImageUrl(this);
     }
 }
 
diff --git a/src/lib/util/generateImageUrl.ts b/src/lib/util/generateImageUrl.ts
new file mode 100644
index 0000000000..77110194a2
--- /dev/null
+++ b/src/lib/util/generateImageUrl.ts
@@ -0,0 +1,11 @@
+import gravatarUrl from 'gravatar-url';
+
+export const generateImageUrl = (user: {
+    email: string;
+    username: string;
+    id: number;
+}): string =>
+    gravatarUrl(user.email || user.username || String(user.id), {
+        size: 42,
+        default: 'retro',
+    });