diff --git a/docs_src/body_nested_models/tutorial004.py b/docs_src/body_nested_models/tutorial004.py
index 6037b32b7..311a4e73f 100644
--- a/docs_src/body_nested_models/tutorial004.py
+++ b/docs_src/body_nested_models/tutorial004.py
@@ -16,7 +16,7 @@ class Item(BaseModel):
     description: Optional[str] = None
     price: float
     tax: Optional[float] = None
-    tags: Set[str] = []
+    tags: Set[str] = set()
     image: Optional[Image] = None
 
 
diff --git a/docs_src/body_nested_models/tutorial004_py310.py b/docs_src/body_nested_models/tutorial004_py310.py
index ab0b63db1..e5dbf6e0b 100644
--- a/docs_src/body_nested_models/tutorial004_py310.py
+++ b/docs_src/body_nested_models/tutorial004_py310.py
@@ -14,7 +14,7 @@ class Item(BaseModel):
     description: str | None = None
     price: float
     tax: float | None = None
-    tags: set[str] = []
+    tags: set[str] = set()
     image: Image | None = None
 
 
diff --git a/docs_src/body_nested_models/tutorial004_py39.py b/docs_src/body_nested_models/tutorial004_py39.py
index 19985ec7a..ab05da023 100644
--- a/docs_src/body_nested_models/tutorial004_py39.py
+++ b/docs_src/body_nested_models/tutorial004_py39.py
@@ -16,7 +16,7 @@ class Item(BaseModel):
     description: Optional[str] = None
     price: float
     tax: Optional[float] = None
-    tags: set[str] = []
+    tags: set[str] = set()
     image: Optional[Image] = None