diff --git a/CHANGES.md b/CHANGES.md
index 18bab5131e6..975de8a131f 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -16,6 +16,7 @@
 
 - Additional cases of immediately nested tuples, lists, and dictionaries are now
   indented less (#4012)
+- Keep suites consisting of an ellipsis followed by a comment on their own lines (#4066)
 
 ### Configuration
 
diff --git a/src/black/nodes.py b/src/black/nodes.py
index de53f8e36a3..fcfd6c9bae3 100644
--- a/src/black/nodes.py
+++ b/src/black/nodes.py
@@ -765,6 +765,10 @@ def is_stub_body(node: LN) -> bool:
     if len(node.children) != 2:
         return False
 
+    # If there is a comment after the ..., don't treat this suite as a stub body.
+    if node.children[1].prefix.strip():
+        return False
+
     child = node.children[0]
     return (
         not child.prefix.strip()
diff --git a/tests/data/cases/preview_dummy_implementations.py b/tests/data/cases/preview_dummy_implementations.py
index 98b69bf87b2..38087def4cf 100644
--- a/tests/data/cases/preview_dummy_implementations.py
+++ b/tests/data/cases/preview_dummy_implementations.py
@@ -48,6 +48,9 @@ def b(arg: Union[int, str, object]) -> Union[int, str]:
         raise TypeError
     return arg
 
+def has_comment():
+    ...  # not a dummy
+
 # output
 
 from typing import NoReturn, Protocol, Union, overload
@@ -98,3 +101,7 @@ def b(arg: Union[int, str, object]) -> Union[int, str]:
     if not isinstance(arg, (int, str)):
         raise TypeError
     return arg
+
+
+def has_comment():
+    ...  # not a dummy