diff --git a/client/less/main.less b/client/less/main.less
index 76867f47073..bb6c33e3d2e 100644
--- a/client/less/main.less
+++ b/client/less/main.less
@@ -1175,6 +1175,11 @@ and (max-width : 400px)  {
   font-size: 17px;
 }
 
+// Challange editor CSS for iOS.  Issue 9104.
+.editorScrollDiv {
+  -webkit-overflow-scrolling: touch;
+}
+
 @import "chat.less";
 @import "jobs.less";
 @import "challenge.less";