diff --git a/src/utils/Dragger.ts b/src/utils/Dragger.ts
index b04f309e3..ec735d8de 100644
--- a/src/utils/Dragger.ts
+++ b/src/utils/Dragger.ts
@@ -398,7 +398,7 @@ export default class Dragger {
     const { doc } = this.opts;
     el = el || this.el;
 
-    if (!this.docs) {
+    if (!this.docs.length) {
       const docs = [document];
       el && docs.push(el.ownerDocument);
       doc && docs.push(doc);