diff --git a/spacy/tokens/doc.pyi b/spacy/tokens/doc.pyi
index 9d45960ab..353983fd0 100644
--- a/spacy/tokens/doc.pyi
+++ b/spacy/tokens/doc.pyi
@@ -1,16 +1,30 @@
-from typing import Callable, Protocol, Iterable, Iterator, Optional
-from typing import Union, Tuple, List, Dict, Any, overload
+from pathlib import Path
+from typing import (
+    Any,
+    Callable,
+    Dict,
+    Iterable,
+    Iterator,
+    List,
+    Optional,
+    Protocol,
+    Sequence,
+    Tuple,
+    Union,
+    overload,
+)
+
+import numpy as np
 from cymem.cymem import Pool
 from thinc.types import Floats1d, Floats2d, Ints2d
-from .span import Span
-from .token import Token
-from ._dict_proxies import SpanGroups
-from ._retokenize import Retokenizer
+
 from ..lexeme import Lexeme
 from ..vocab import Vocab
+from ._dict_proxies import SpanGroups
+from ._retokenize import Retokenizer
+from .span import Span
+from .token import Token
 from .underscore import Underscore
-from pathlib import Path
-import numpy as np
 
 class DocMethod(Protocol):
     def __call__(self: Doc, *args: Any, **kwargs: Any) -> Any: ...  # type: ignore[misc]
@@ -119,7 +133,12 @@ class Doc:
     def text(self) -> str: ...
     @property
     def text_with_ws(self) -> str: ...
-    ents: Tuple[Span]
+    # Ideally the getter would output Tuple[Span]
+    # see https://github.com/python/mypy/issues/3004
+    @property
+    def ents(self) -> Sequence[Span]: ...
+    @ents.setter
+    def ents(self, value: Sequence[Span]) -> None: ...
     def set_ents(
         self,
         entities: List[Span],
diff --git a/spacy/training/corpus.py b/spacy/training/corpus.py
index 086ad831c..f05d09bcb 100644
--- a/spacy/training/corpus.py
+++ b/spacy/training/corpus.py
@@ -1,16 +1,16 @@
-import warnings
-from typing import Union, List, Iterable, Iterator, TYPE_CHECKING, Callable
-from typing import Optional
-from pathlib import Path
 import random
+import warnings
+from pathlib import Path
+from typing import TYPE_CHECKING, Callable, Iterable, List, Optional, Protocol, Union
+
 import srsly
 
 from .. import util
+from ..errors import Errors, Warnings
+from ..tokens import Doc, DocBin
+from ..vocab import Vocab
 from .augment import dont_augment
 from .example import Example
-from ..errors import Warnings, Errors
-from ..tokens import DocBin, Doc
-from ..vocab import Vocab
 
 if TYPE_CHECKING:
     # This lets us add type hints for mypy etc. without causing circular imports
@@ -19,6 +19,11 @@ if TYPE_CHECKING:
 FILE_TYPE = ".spacy"
 
 
+class ReaderProtocol(Protocol):
+    def __call__(self, nlp: "Language") -> Iterable[Example]:
+        pass
+
+
 @util.registry.readers("spacy.Corpus.v1")
 def create_docbin_reader(
     path: Optional[Path],
@@ -26,7 +31,7 @@ def create_docbin_reader(
     max_length: int = 0,
     limit: int = 0,
     augmenter: Optional[Callable] = None,
-) -> Callable[["Language"], Iterable[Example]]:
+) -> ReaderProtocol:
     if path is None:
         raise ValueError(Errors.E913)
     util.logger.debug("Loading corpus from path: %s", path)
@@ -45,7 +50,7 @@ def create_jsonl_reader(
     min_length: int = 0,
     max_length: int = 0,
     limit: int = 0,
-) -> Callable[["Language"], Iterable[Example]]:
+) -> ReaderProtocol:
     return JsonlCorpus(path, min_length=min_length, max_length=max_length, limit=limit)
 
 
@@ -63,7 +68,7 @@ def create_plain_text_reader(
     path: Optional[Path],
     min_length: int = 0,
     max_length: int = 0,
-) -> Callable[["Language"], Iterable[Doc]]:
+) -> ReaderProtocol:
     """Iterate Example objects from a file or directory of plain text
     UTF-8 files with one line per doc.
 
@@ -144,7 +149,7 @@ class Corpus:
         self.augmenter = augmenter if augmenter is not None else dont_augment
         self.shuffle = shuffle
 
-    def __call__(self, nlp: "Language") -> Iterator[Example]:
+    def __call__(self, nlp: "Language") -> Iterable[Example]:
         """Yield examples from the data.
 
         nlp (Language): The current nlp object.
@@ -182,7 +187,7 @@ class Corpus:
 
     def make_examples(
         self, nlp: "Language", reference_docs: Iterable[Doc]
-    ) -> Iterator[Example]:
+    ) -> Iterable[Example]:
         for reference in reference_docs:
             if len(reference) == 0:
                 continue
@@ -197,7 +202,7 @@ class Corpus:
 
     def make_examples_gold_preproc(
         self, nlp: "Language", reference_docs: Iterable[Doc]
-    ) -> Iterator[Example]:
+    ) -> Iterable[Example]:
         for reference in reference_docs:
             if reference.has_annotation("SENT_START"):
                 ref_sents = [sent.as_doc() for sent in reference.sents]
@@ -210,7 +215,7 @@ class Corpus:
 
     def read_docbin(
         self, vocab: Vocab, locs: Iterable[Union[str, Path]]
-    ) -> Iterator[Doc]:
+    ) -> Iterable[Doc]:
         """Yield training examples as example dicts"""
         i = 0
         for loc in locs:
@@ -257,7 +262,7 @@ class JsonlCorpus:
         self.max_length = max_length
         self.limit = limit
 
-    def __call__(self, nlp: "Language") -> Iterator[Example]:
+    def __call__(self, nlp: "Language") -> Iterable[Example]:
         """Yield examples from the data.
 
         nlp (Language): The current nlp object.
@@ -307,7 +312,7 @@ class PlainTextCorpus:
         self.min_length = min_length
         self.max_length = max_length
 
-    def __call__(self, nlp: "Language") -> Iterator[Example]:
+    def __call__(self, nlp: "Language") -> Iterable[Example]:
         """Yield examples from the data.
 
         nlp (Language): The current nlp object.