diff --git a/src/_pytest/_io/saferepr.py b/src/_pytest/_io/saferepr.py
index 47a00de60..6b9f353a2 100644
--- a/src/_pytest/_io/saferepr.py
+++ b/src/_pytest/_io/saferepr.py
@@ -1,9 +1,12 @@
 import pprint
 import reprlib
 from typing import Any
+from typing import Dict
+from typing import IO
+from typing import Optional
 
 
-def _try_repr_or_str(obj):
+def _try_repr_or_str(obj: object) -> str:
     try:
         return repr(obj)
     except (KeyboardInterrupt, SystemExit):
@@ -12,7 +15,7 @@ def _try_repr_or_str(obj):
         return '{}("{}")'.format(type(obj).__name__, obj)
 
 
-def _format_repr_exception(exc: BaseException, obj: Any) -> str:
+def _format_repr_exception(exc: BaseException, obj: object) -> str:
     try:
         exc_info = _try_repr_or_str(exc)
     except (KeyboardInterrupt, SystemExit):
@@ -42,7 +45,7 @@ class SafeRepr(reprlib.Repr):
         self.maxstring = maxsize
         self.maxsize = maxsize
 
-    def repr(self, x: Any) -> str:
+    def repr(self, x: object) -> str:
         try:
             s = super().repr(x)
         except (KeyboardInterrupt, SystemExit):
@@ -51,7 +54,7 @@ class SafeRepr(reprlib.Repr):
             s = _format_repr_exception(exc, x)
         return _ellipsize(s, self.maxsize)
 
-    def repr_instance(self, x: Any, level: int) -> str:
+    def repr_instance(self, x: object, level: int) -> str:
         try:
             s = repr(x)
         except (KeyboardInterrupt, SystemExit):
@@ -61,7 +64,7 @@ class SafeRepr(reprlib.Repr):
         return _ellipsize(s, self.maxsize)
 
 
-def safeformat(obj: Any) -> str:
+def safeformat(obj: object) -> str:
     """return a pretty printed string for the given object.
     Failing __repr__ functions of user instances will be represented
     with a short exception info.
@@ -72,7 +75,7 @@ def safeformat(obj: Any) -> str:
         return _format_repr_exception(exc, obj)
 
 
-def saferepr(obj: Any, maxsize: int = 240) -> str:
+def saferepr(obj: object, maxsize: int = 240) -> str:
     """return a size-limited safe repr-string for the given object.
     Failing __repr__ functions of user instances will be represented
     with a short exception info and 'saferepr' generally takes
@@ -85,19 +88,39 @@ def saferepr(obj: Any, maxsize: int = 240) -> str:
 class AlwaysDispatchingPrettyPrinter(pprint.PrettyPrinter):
     """PrettyPrinter that always dispatches (regardless of width)."""
 
-    def _format(self, object, stream, indent, allowance, context, level):
-        p = self._dispatch.get(type(object).__repr__, None)
+    def _format(
+        self,
+        object: object,
+        stream: IO[str],
+        indent: int,
+        allowance: int,
+        context: Dict[int, Any],
+        level: int,
+    ) -> None:
+        # Type ignored because _dispatch is private.
+        p = self._dispatch.get(type(object).__repr__, None)  # type: ignore[attr-defined] # noqa: F821
 
         objid = id(object)
         if objid in context or p is None:
-            return super()._format(object, stream, indent, allowance, context, level)
+            # Type ignored because _format is private.
+            super()._format(  # type: ignore[misc] # noqa: F821
+                object, stream, indent, allowance, context, level,
+            )
+            return
 
         context[objid] = 1
         p(self, object, stream, indent, allowance, context, level + 1)
         del context[objid]
 
 
-def _pformat_dispatch(object, indent=1, width=80, depth=None, *, compact=False):
+def _pformat_dispatch(
+    object: object,
+    indent: int = 1,
+    width: int = 80,
+    depth: Optional[int] = None,
+    *,
+    compact: bool = False
+) -> str:
     return AlwaysDispatchingPrettyPrinter(
         indent=indent, width=width, depth=depth, compact=compact
     ).pformat(object)
diff --git a/src/_pytest/assertion/__init__.py b/src/_pytest/assertion/__init__.py
index 997c17921..6504db574 100644
--- a/src/_pytest/assertion/__init__.py
+++ b/src/_pytest/assertion/__init__.py
@@ -3,8 +3,8 @@ support for presenting detailed information in failing assertions.
 """
 import sys
 from typing import Any
-from typing import List
 from typing import Generator
+from typing import List
 from typing import Optional
 
 from _pytest.assertion import rewrite