diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index 41dbae907c10cfd83913ef270370dd3e517930a5..0c7ac05e3932e37bbce5c5f396a7854c72c48f42 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -1693,7 +1693,7 @@ function theme_user_signature($variables) {
 
   if ($signature) {
     $output .= '<div class="clear">';
-    $output .= '<div>—</div>';
+    $output .= '<div>&mdash;</div>';
     $output .= $signature;
     $output .= '</div>';
   }