diff --git a/static/styles/zulip.css b/static/styles/zulip.css
index 0a699d2a75..626f4a4790 100644
--- a/static/styles/zulip.css
+++ b/static/styles/zulip.css
@@ -2532,6 +2532,12 @@ div.topic_edit_spinner .loading_indicator_spinner {
         }
     }
 
+    /* Override the default border-radius to properly align
+       the button corners with `stream_header_colorblock`. */
+    .dropdown-toggle {
+        border-radius: 1px 4px 4px 1px !important;
+    }
+
     .stream_header_colorblock {
         margin-bottom: 20px;
     }