diff --git a/src/ohmyapi/core/runtime.py b/src/ohmyapi/core/runtime.py
index 576e275..e3d700e 100644
--- a/src/ohmyapi/core/runtime.py
+++ b/src/ohmyapi/core/runtime.py
@@ -154,7 +154,10 @@ class Project:
         tortoise_cfg = self.build_tortoise_config(db_url=db_url)
 
         # Prevent leaking other app's models to Aerich.
-        tortoise_cfg["apps"] = {app_label: tortoise_cfg["apps"][app_label]}
+        if app_label in tortoise_cfg["apps"].keys():
+            tortoise_cfg["apps"] = {app_label: tortoise_cfg["apps"][app_label]}
+        else:
+            tortoise_cfg["apps"] = {app_label: {"default_connection": "default", "models": []}}
 
         # Append aerich.models to the models list of the target app only
         tortoise_cfg["apps"][app_label]["models"].append("aerich.models")
@@ -403,7 +406,7 @@ class App:
         """
         return {
             "models": [
-                f"{self.name}.{m.__name__}" for m in self.models[f"{self.name}.models"]
+                f"{self.name}.{m.__name__}" for m in self._models[f"{self.name}.models"]
             ],
             "middlewares": self.__serialize_middleware(),
             "routes": self.__serialize_router(),