diff --git a/plugins/modules/ipatrust.py b/plugins/modules/ipatrust.py
index 6251ecc821..0c7aac5f8f 100644
--- a/plugins/modules/ipatrust.py
+++ b/plugins/modules/ipatrust.py
@@ -190,7 +190,8 @@ def main():
             state=dict(type="str", default="present",
                        choices=["present", "absent"]),
             # present
-            trust_type=dict(type="str", default="ad", required=False),
+            trust_type=dict(type="str", default="ad", required=False,
+                            choices=["ad"]),
             admin=dict(type="str", default=None, required=False),
             password=dict(type="str", default=None,
                           required=False, no_log=True),