diff --git a/app/assets/javascripts/discourse/app/controllers/create-account.js b/app/assets/javascripts/discourse/app/controllers/create-account.js
index 08d19fdb416..3c9c7fe3411 100644
--- a/app/assets/javascripts/discourse/app/controllers/create-account.js
+++ b/app/assets/javascripts/discourse/app/controllers/create-account.js
@@ -74,6 +74,14 @@ export default Controller.extend(
       return false;
     },
 
+    @discourseComputed("userFields", "hasAtLeastOneLoginButton")
+    modalBodyClasses(userFields, hasAtLeastOneLoginButton) {
+      const classes = [];
+      if (userFields) classes.push("has-user-fields");
+      if (hasAtLeastOneLoginButton) classes.push("has-alt-auth");
+      return classes.join(" ");
+    },
+
     @discourseComputed("authOptions", "authOptions.can_edit_username")
     usernameDisabled(authOptions, canEditUsername) {
       return authOptions && !canEditUsername;
diff --git a/app/assets/javascripts/discourse/app/templates/modal/create-account.hbs b/app/assets/javascripts/discourse/app/templates/modal/create-account.hbs
index 2edb94b483e..a353fb0f889 100644
--- a/app/assets/javascripts/discourse/app/templates/modal/create-account.hbs
+++ b/app/assets/javascripts/discourse/app/templates/modal/create-account.hbs
@@ -1,7 +1,7 @@
 {{#create-account email=accountEmail disabled=submitDisabled action=(action "createAccount")}}
   {{#unless complete}}
     {{plugin-outlet name="create-account-before-modal-body"}}
-    {{#d-modal-body title="create_account.title" class=(concat (if hasAtLeastOneLoginButton "has-alt-auth") " " (if userFields "has-user-fields"))}}
+    {{#d-modal-body title="create_account.title" class=modalBodyClasses}}
 
       {{#unless hasAuthOptions}}
         {{login-buttons externalLogin=(action "externalLogin")}}