diff --git a/manifests/guestagent.pp b/manifests/guestagent.pp
index bc6b767e..9ff707f0 100644
--- a/manifests/guestagent.pp
+++ b/manifests/guestagent.pp
@@ -72,16 +72,16 @@
 #   (optional) Default password Length for root password.
 #   Defaults to $::os_service_default.
 #
-# [*backup_aes_cbc_key*]
-#   (optional) Default OpenSSL aes_cbc key
-#   Defaults to $::os_service_default.
-#
 #  DEPRECATED PARAMETERS
 #
 # [*control_exchange*]
 #   (Optional) Moved to init.pp. The default exchange to scope topics.
 #   Defaults to undef.
 #
+# [*backup_aes_cbc_key*]
+#   (optional) Default OpenSSL aes_cbc key
+#   Defaults to undef
+#
 class trove::guestagent(
   $enabled                 = true,
   $manage_service          = true,
@@ -98,9 +98,9 @@ class trove::guestagent(
   $root_grant              = $::os_service_default,
   $root_grant_option       = $::os_service_default,
   $default_password_length = $::os_service_default,
-  $backup_aes_cbc_key      = $::os_service_default,
   #Deprecated
   $control_exchange        = undef,
+  $backup_aes_cbc_key      = undef,
 ) inherits trove {
 
   include trove::deps
@@ -112,6 +112,10 @@ class trove::guestagent(
 trove::control_exchange instead.")
   }
 
+  if $backup_aes_cbc_key != undef {
+    warning('The parameter backup_aes_cbc_key is deprecated for removal')
+  }
+
   # basic service config
   trove_guestagent_config {
     'DEFAULT/swift_url':               value => $swift_url;
@@ -119,7 +123,7 @@ trove::control_exchange instead.")
     'DEFAULT/root_grant':              value => $root_grant;
     'DEFAULT/root_grant_option':       value => $root_grant_option;
     'DEFAULT/default_password_length': value => $default_password_length;
-    'DEFAULT/backup_aes_cbc_key':      value => $backup_aes_cbc_key;
+    'DEFAULT/backup_aes_cbc_key':      value => pick($backup_aes_cbc_key, $::os_service_default);
   }
 
   oslo::messaging::default { 'trove_guestagent_config':
diff --git a/releasenotes/notes/deprecate-guestagent-backup_aes_cbc_key-84ed0dd16e26c8b9.yaml b/releasenotes/notes/deprecate-guestagent-backup_aes_cbc_key-84ed0dd16e26c8b9.yaml
new file mode 100644
index 00000000..7513c379
--- /dev/null
+++ b/releasenotes/notes/deprecate-guestagent-backup_aes_cbc_key-84ed0dd16e26c8b9.yaml
@@ -0,0 +1,5 @@
+---
+deprecations:
+  - |
+    The ``trove::guestagent::backup_aes_cbc_key`` parameter has been deprecated
+    because the actual parameter in Trove was already deprecated.