diff --git a/.mypy.ini b/.mypy.ini
index 0b241fe889a..b5cedf90b7c 100644
--- a/.mypy.ini
+++ b/.mypy.ini
@@ -20,9 +20,6 @@ warn_unused_ignores = True
 disallow_any_unimported = True
 warn_return_any = True
 
-[mypy-tests.*]
-disallow_untyped_defs = False
-
 [mypy-aiodns]
 ignore_missing_imports = True
 
diff --git a/CHANGES/5829.misc b/CHANGES/5829.misc
new file mode 100644
index 00000000000..5a892ed54e0
--- /dev/null
+++ b/CHANGES/5829.misc
@@ -0,0 +1 @@
+Disallow untyped defs on internal tests.