diff --git a/components/script/dom/node.rs b/components/script/dom/node.rs
index a93389638fe..86d952146a4 100644
--- a/components/script/dom/node.rs
+++ b/components/script/dom/node.rs
@@ -355,6 +355,7 @@ impl Node {
             // Out-of-document elements never have the descendants flag set.
             node.set_flag(
                 NodeFlags::IS_IN_DOC |
+                    NodeFlags::IS_CONNECTED |
                     NodeFlags::HAS_DIRTY_DESCENDANTS |
                     NodeFlags::HAS_SNAPSHOT |
                     NodeFlags::HANDLED_SNAPSHOT,