diff --git a/numpydoc/tests/test_validate.py b/numpydoc/tests/test_validate.py
index a0b30b9d..f3be498b 100644
--- a/numpydoc/tests/test_validate.py
+++ b/numpydoc/tests/test_validate.py
@@ -1862,6 +1862,9 @@ def test_cached_property(self):
     def test_three_decorators(self):
         """Test method with three decorators."""
 
+    async def test_async(self):
+        """Test async method."""
+
 
 class TestValidatorClass:
     @pytest.mark.parametrize("invalid_name", ["unknown_mod", "unknown_mod.MyClass"])
@@ -1903,6 +1906,10 @@ def test_raises_for_invalid_attribute_name(self, invalid_name):
                 "numpydoc.tests.test_validate.DecoratorClass.test_three_decorators",
                 getsourcelines(DecoratorClass.test_three_decorators)[-1] + 3,
             ],
+            [
+                "numpydoc.tests.test_validate.DecoratorClass.test_async",
+                getsourcelines(DecoratorClass.test_async)[-1],
+            ],
         ],
     )
     def test_source_file_def_line_with_decorators(self, decorated_obj, def_line):
diff --git a/numpydoc/validate.py b/numpydoc/validate.py
index 30b0f413..235841ea 100644
--- a/numpydoc/validate.py
+++ b/numpydoc/validate.py
@@ -328,7 +328,8 @@ def source_file_def_line(self):
             def_line = next(
                 i
                 for i, x in enumerate(
-                    re.match("^ *(def|class) ", s) for s in sourcelines[0]
+                    re.match(r"^\s*(async\s+)?(?:def|class)\s+", s)
+                    for s in sourcelines[0]
                 )
                 if x is not None
             )