diff --git a/src/applications/people/cache/PhabricatorUserPreferencesCacheType.php b/src/applications/people/cache/PhabricatorUserPreferencesCacheType.php
--- a/src/applications/people/cache/PhabricatorUserPreferencesCacheType.php
+++ b/src/applications/people/cache/PhabricatorUserPreferencesCacheType.php
@@ -31,19 +31,39 @@
       ->setViewer($viewer)
       ->withUserPHIDs($user_phids)
       ->execute();
+    $preferences = mpull($preferences, null, 'getUserPHID');
+
+    // If some users don't have settings of their own yet, we need to load
+    // the global default settings to generate caches for them.
+    if (count($preferences) < count($user_phids)) {
+      $global = id(new PhabricatorUserPreferencesQuery())
+        ->setViewer($viewer)
+        ->withBuiltinKeys(
+          array(
+            PhabricatorUserPreferences::BUILTIN_GLOBAL_DEFAULT,
+          ))
+        ->executeOne();
+    } else {
+      $global = null;
+    }
 
     $all_settings = PhabricatorSetting::getAllSettings();
 
     $settings = array();
-    foreach ($preferences as $preference) {
-      $user_phid = $preference->getUserPHID();
+    foreach ($users as $user_phid => $user) {
+      $preference = idx($preferences, $user_phid, $global);
+
+      if (!$preference) {
+        continue;
+      }
+
       foreach ($all_settings as $key => $setting) {
         $value = $preference->getSettingValue($key);
 
         // As an optimization, we omit the value from the cache if it is
         // exactly the same as the hardcoded default.
         $default_value = id(clone $setting)
-          ->setViewer($users[$user_phid])
+          ->setViewer($user)
           ->getSettingDefaultValue();
         if ($value === $default_value) {
           continue;
diff --git a/src/applications/settings/storage/PhabricatorUserPreferences.php b/src/applications/settings/storage/PhabricatorUserPreferences.php
--- a/src/applications/settings/storage/PhabricatorUserPreferences.php
+++ b/src/applications/settings/storage/PhabricatorUserPreferences.php
@@ -130,9 +130,23 @@
       return $preferences;
     }
 
-    return id(new self())
+    $preferences = id(new self())
       ->setUserPHID($user->getPHID())
       ->attachUser($user);
+
+    $global = id(new PhabricatorUserPreferencesQuery())
+      ->setViewer($user)
+      ->withBuiltinKeys(
+        array(
+          self::BUILTIN_GLOBAL_DEFAULT,
+        ))
+      ->executeOne();
+
+    if ($global) {
+      $preferences->attachDefaultSettings($global);
+    }
+
+    return $preferences;
   }
 
   public function newTransaction($key, $value) {