diff --git a/CHANGELOG.md b/CHANGELOG.md
index e466ee5a..a75b3fc5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 1.15.1
+
+- Fix `fully_qualified` should be `typehints_fully_qualified`
+
 ## 1.15.0
 
 - Resolve type guard imports before evaluating annotations for objects
diff --git a/src/sphinx_autodoc_typehints/__init__.py b/src/sphinx_autodoc_typehints/__init__.py
index 492c35d2..5ecff688 100644
--- a/src/sphinx_autodoc_typehints/__init__.py
+++ b/src/sphinx_autodoc_typehints/__init__.py
@@ -121,7 +121,7 @@ def format_annotation(annotation: Any, config: Config) -> str:
         module = "typing"
 
     full_name = f"{module}.{class_name}" if module != "builtins" else class_name
-    fully_qualified: bool = getattr(config, "fully_qualified", False)
+    fully_qualified: bool = getattr(config, "typehints_fully_qualified", False)
     prefix = "" if fully_qualified or full_name == class_name else "~"
     role = "data" if class_name in _PYDATA_ANNOTATIONS else "class"
     args_format = "\\[{}]"
diff --git a/tests/test_sphinx_autodoc_typehints.py b/tests/test_sphinx_autodoc_typehints.py
index e5a9b4cd..aa366636 100644
--- a/tests/test_sphinx_autodoc_typehints.py
+++ b/tests/test_sphinx_autodoc_typehints.py
@@ -221,14 +221,14 @@ def test_format_annotation(inv: Inventory, annotation: Any, expected_result: str
         # Test with the "fully_qualified" flag turned on
         if "typing" in expected_result_not_simplified:
             expected_result_not_simplified = expected_result_not_simplified.replace("~typing", "typing")
-            conf = create_autospec(Config, fully_qualified=True, simplify_optional_unions=False)
+            conf = create_autospec(Config, typehints_fully_qualified=True, simplify_optional_unions=False)
             assert format_annotation(annotation, conf) == expected_result_not_simplified
 
     # Test with the "fully_qualified" flag turned on
     if "typing" in expected_result or __name__ in expected_result:
         expected_result = expected_result.replace("~typing", "typing")
         expected_result = expected_result.replace("~" + __name__, __name__)
-        conf = create_autospec(Config, fully_qualified=True)
+        conf = create_autospec(Config, typehints_fully_qualified=True)
         assert format_annotation(annotation, conf) == expected_result
 
     # Test for the correct role (class vs data) using the official Sphinx inventory