diff --git a/roles/proxmox_upgrade/tasks/drain.yml b/roles/proxmox_upgrade/tasks/drain.yml
index eab55e9..327bee7 100644
--- a/roles/proxmox_upgrade/tasks/drain.yml
+++ b/roles/proxmox_upgrade/tasks/drain.yml
@@ -18,7 +18,7 @@
     api_base = "https://{{ api_host }}:{{ api_port }}/api2/json"
     headers  = {"Authorization": "PVEAPIToken={{ api_token_id }}={{ api_token_secret }}"}
     node     = "{{ current_node }}"
-    shared   = {{ shared_storage | lower }}
+    shared   = {{ shared_storage | lower | replace("true", "True") | replace("false", "False") }}
     exclude_tags = {{ migrate_exclude_tags | to_json }}
 
     def api_get(path):
@@ -222,4 +222,4 @@
       loop: "{{ migration_plan | selectattr('needs_fallback') | list }}"
       loop_control:
         loop_var: guest
-      when: live_migrate_fallback != 'skip'
+      when: live_migrate_fallback != 'skip'
\ No newline at end of file