diff --git a/gdk/broadway/client.html b/gdk/broadway/client.html
index 14e61e5770..43a74ad28b 100644
--- a/gdk/broadway/client.html
+++ b/gdk/broadway/client.html
@@ -43,6 +43,11 @@
     text-shadow: black -1px 0 0, black 1px 0 0, black 0 1px 0, black 0 -1px 0;
     font-weight: bold;
     cursor: pointer;
+    -webkit-user-select: none;
+    -khtml-user-select: none;
+    -moz-user-select: none;
+    -o-user-select: none;
+    user-select: none;
 }
 
 .frame-close:focus {