diff --git a/core/themes/seven/style.css b/core/themes/seven/style.css
index 9c4fff4..c87f89f 100644
--- a/core/themes/seven/style.css
+++ b/core/themes/seven/style.css
@@ -648,6 +648,7 @@ select.form-select {
   -webkit-transition: border linear 0.2s, box-shadow linear 0.2s;
   -moz-transition: border linear 0.2s, box-shadow linear 0.2s;
   transition: border linear 0.2s, box-shadow linear 0.2s;
+  max-width: 100%;
 }
 input.form-text:focus,
 input.form-tel:focus,