diff --git a/core/themes/seven/css/components/dropbutton.component.css b/core/themes/seven/css/components/dropbutton.component.css
index 229f1bd..fdce85d 100644
--- a/core/themes/seven/css/components/dropbutton.component.css
+++ b/core/themes/seven/css/components/dropbutton.component.css
@@ -162,10 +162,16 @@
  * Copied from Seven's buttons.css.
  */
 .dropbutton-single .dropbutton-widget {
-  border: 0;
+  border-width: 1px;
+  border-radius: 20em;
   position: static;
   display: inline-block;
 }
+.dropbutton-single .dropbutton-widget .dropbutton-action a,
+.dropbutton-single .dropbutton-widget .dropbutton-action input,
+.dropbutton-single .dropbutton-widget .dropbutton-action button {
+  border-radius: 20em;
+}
 .dropbutton-single .dropbutton-action a {
   padding: 4px 1.5em;
   border: 1px solid #a6a6a6;
diff --git a/core/themes/stable/css/core/dropbutton/dropbutton.css b/core/themes/stable/css/core/dropbutton/dropbutton.css
index 5990514..5f32101 100644
--- a/core/themes/stable/css/core/dropbutton/dropbutton.css
+++ b/core/themes/stable/css/core/dropbutton/dropbutton.css
@@ -18,7 +18,11 @@
 }
 
 @media screen and (max-width:600px) {
-  .js .dropbutton-wrapper {
+  .js .dropbutton-wrapper,
+  .js .dropbutton-single {
+    width: 100%;
+  }
+  .js .dropbutton-single .dropbutton-widget {
     width: 100%;
   }
 }