diff --git a/paper-menu-button.html b/paper-menu-button.html
index 8fba201..3875a91 100644
--- a/paper-menu-button.html
+++ b/paper-menu-button.html
@@ -93,6 +93,11 @@
         @apply(--paper-menu-button-content);
       }
 
+      .dropdown-content ::content > * {
+        /* Ensure items are full width so they don't wrap during animation. */
+        white-space: nowrap;
+      }
+
       :host([vertical-align="top"]) .dropdown-content {
         margin-bottom: 20px;
         margin-top: -10px;