diff --git a/lib/SimpleSAML/XHTML/Template.php b/lib/SimpleSAML/XHTML/Template.php
index 0d660309dff538a7db2cc94068bcffb32f11dc83..9f77c111c4fe9adf233a08e86dfed8a9e94dc83f 100644
--- a/lib/SimpleSAML/XHTML/Template.php
+++ b/lib/SimpleSAML/XHTML/Template.php
@@ -178,11 +178,13 @@ class SimpleSAML_XHTML_Template
             return false;
         }
 
-
         // load extra i18n domains
         if ($this->module) {
             $this->localization->addModuleDomain($this->module);
         }
+        if ($this->theme['module'] !== null && $this->theme['module'] !== $this->module) {
+            $this->localization->addModuleDomain($this->theme['module']);
+        }
 
         $options = array(
             'cache' => $cache,