diff --git a/changelogs/fragments/fix-string-formatting-error-on-deprecated-server-type-warning.yml b/changelogs/fragments/fix-string-formatting-error-on-deprecated-server-type-warning.yml
new file mode 100644
index 0000000..ce2b9da
--- /dev/null
+++ b/changelogs/fragments/fix-string-formatting-error-on-deprecated-server-type-warning.yml
@@ -0,0 +1,2 @@
+bugfixes:
+  - hcloud_server - Fix string formatting error on deprecated server type warning
diff --git a/plugins/modules/hcloud_server.py b/plugins/modules/hcloud_server.py
index 81cba32..eceb4f7 100644
--- a/plugins/modules/hcloud_server.py
+++ b/plugins/modules/hcloud_server.py
@@ -548,7 +548,7 @@ class AnsibleHCloudServer(AnsibleHCloud):
             )
         else:
             self.module.warn(
-                "Attention: The server plan % is deprecated and will no longer be available for order as of "
+                "Attention: The server plan %s is deprecated and will no longer be available for order as of "
                 % server_type.name
                 + "%s. Existing servers of that plan will continue to work as before "
                 % server_type.deprecation.unavailable_after.strftime("%Y-%m-%d")