diff --git a/moto/iot/models.py b/moto/iot/models.py
index 1b10c09f..ce7a4cf5 100644
--- a/moto/iot/models.py
+++ b/moto/iot/models.py
@@ -32,6 +32,7 @@ class FakeThing(BaseModel):
     def to_dict(self, include_default_client_id=False):
         obj = {
             'thingName': self.thing_name,
+            'thingArn': self.arn,
             'attributes': self.attributes,
             'version': self.version
         }