diff --git a/resources/static/dialog/css/m.css b/resources/static/dialog/css/m.css
index 6412f9d7c05ee78dd6481afd33d3eba1b9e336b5..bf3a752178c4907763210c46edf9d98fc905e850 100644
--- a/resources/static/dialog/css/m.css
+++ b/resources/static/dialog/css/m.css
@@ -196,5 +196,13 @@
   .inputs > li {
     margin-top: 12px;
   }
+
+  /* The unsupported and cookies_disabled dialogs have to be position: static
+   * or else their content is not displayed on mobile devices. See issue #1998
+   */
+  #error.unsupported, #error.cookies_disabled {
+    position: static;
+    height: 250px;
+  }
 }