diff --git a/lib/ansible/modules/cloud/vmware/vmware_guest.py b/lib/ansible/modules/cloud/vmware/vmware_guest.py
index ba78418b987..71c2cff2f3c 100644
--- a/lib/ansible/modules/cloud/vmware/vmware_guest.py
+++ b/lib/ansible/modules/cloud/vmware/vmware_guest.py
@@ -699,7 +699,8 @@ class PyVmomiHelper(PyVmomi):
         if vm_creation and self.params['guest_id'] is None:
             self.module.fail_json(msg="guest_id attribute is mandatory for VM creation")
 
-        if self.params['guest_id'] and (vm_obj is None or self.params['guest_id'] != vm_obj.summary.config.guestId):
+        if self.params['guest_id'] and \
+                (vm_obj is None or self.params['guest_id'].lower() != vm_obj.summary.config.guestId.lower()):
             self.change_detected = True
             self.configspec.guestId = self.params['guest_id']