diff --git a/scrapy/utils/deprecate.py b/scrapy/utils/deprecate.py
index 31e76fc3a..a53802291 100644
--- a/scrapy/utils/deprecate.py
+++ b/scrapy/utils/deprecate.py
@@ -65,10 +65,11 @@ def create_deprecated_class(
     # deprecated_class() takes the module of the alias from its calling frame,
     # which is this function and the decorator wrapping it, so skip past both.
     frame = inspect.currentframe()
-    while frame is not None and frame.f_globals.get("__name__") in _WRAPPER_MODULES:
+    assert frame is not None
+    while frame.f_globals.get("__name__") in _WRAPPER_MODULES:
+        assert frame.f_back is not None
         frame = frame.f_back
-    if frame is not None:
-        cls.__module__ = frame.f_globals.get("__name__", cls.__module__)
+    cls.__module__ = frame.f_globals.get("__name__", cls.__module__)
     return cls
 
 
diff --git a/tests/test_utils_deprecate.py b/tests/test_utils_deprecate.py
index df92bfa1e..5d95e4776 100644
--- a/tests/test_utils_deprecate.py
+++ b/tests/test_utils_deprecate.py
@@ -6,13 +6,22 @@ from unittest import mock
 import pytest
 
 from scrapy.exceptions import ScrapyDeprecationWarning
-from scrapy.utils.deprecate import create_deprecated_class, update_classpath
+from scrapy.utils.deprecate import attribute, create_deprecated_class, update_classpath
 
 
 class NewName:
     pass
 
 
+def test_attribute():
+    with pytest.warns(
+        ScrapyDeprecationWarning,
+        match=r"NewName\.old attribute is deprecated and will be no longer supported"
+        r" in Scrapy 1\.0, use NewName\.new attribute instead",
+    ):
+        attribute(NewName(), "old", "new", version="1.0")
+
+
 class TestCreateDeprecatedClass:
     def test_warns_about_itself(self):
         with pytest.warns(