diff --git a/src/xapi/index.js b/src/xapi/index.js
index 91693e73c..7668567a2 100644
--- a/src/xapi/index.js
+++ b/src/xapi/index.js
@@ -778,7 +778,7 @@ export default class Xapi extends XapiBase {
   }
 
   _assertHealthyVdiChain (vdi) {
-    if (vdi === null) {
+    if (vdi != null) {
       return
     }