diff --git a/lisa/tools/hyperv.py b/lisa/tools/hyperv.py
index 4bf9517166..5d34bb7bbd 100644
--- a/lisa/tools/hyperv.py
+++ b/lisa/tools/hyperv.py
@@ -85,7 +85,7 @@ def get_vm_disks(self, name: str) -> List[VMDisk]:
         # above command returns a list of disks if there are multiple disks.
         # if there is only one disk, it returns a single disk but not a list.
         # so convert the output to a list if it is not already a list
-        if not isinstance(output, List):
+        if not isinstance(output, list):
             output = [output]
         for disk in output:
             vm_disks.append(