diff --git a/changelogs/fragments/7872-proxmox_fix update if setting doesnt exist.yaml b/changelogs/fragments/7872-proxmox_fix update if setting doesnt exist.yaml
new file mode 100644
index 0000000000..82b4fe31d9
--- /dev/null
+++ b/changelogs/fragments/7872-proxmox_fix update if setting doesnt exist.yaml	
@@ -0,0 +1,2 @@
+bugfixes:
+  - proxmox - fix updating a container config if the setting does not already exist (https://github.com/ansible-collections/community.general/pull/7872).
diff --git a/plugins/modules/proxmox.py b/plugins/modules/proxmox.py
index f47ae26e10..2d7b76fde2 100644
--- a/plugins/modules/proxmox.py
+++ b/plugins/modules/proxmox.py
@@ -562,6 +562,10 @@ class ProxmoxLxcAnsible(ProxmoxAnsible):
         # compare the requested config against the current
         update_config = False
         for (arg, value) in kwargs.items():
+            # if the arg isn't in the current config, it needs to be updated
+            if arg not in current_config:
+                update_config = True
+                break
             # some values are lists, the order isn't always the same, so split them and compare by key
             if isinstance(value, str):
                 current_values = current_config[arg].split(",")