diff --git a/core/themes/seven/css/components/form.css b/core/themes/seven/css/components/form.css
index 162db9f98d4aea4d914316b62aeb6815bd24407d..79b342e28a61cac00b59a2ba1477345b2259661d 100644
--- a/core/themes/seven/css/components/form.css
+++ b/core/themes/seven/css/components/form.css
@@ -183,6 +183,13 @@ textarea.form-textarea {
   clear: both;
 }
 
+/**
+ * Limits extra long instances of select elements to the max width allowed
+ * to avoid breaking layouts.
+ */
+select {
+  max-width: 100%;
+}
 
 /**
  * Select elements - Webkit only