diff --git a/stdlib/distutils/command/build_ext.pyi b/stdlib/distutils/command/build_ext.pyi
index 80cd78936..5eb541fb9 100644
--- a/stdlib/distutils/command/build_ext.pyi
+++ b/stdlib/distutils/command/build_ext.pyi
@@ -43,8 +43,8 @@ class build_ext(Command):
     def build_extension(self, ext) -> None: ...
     def swig_sources(self, sources, extension): ...
     def find_swig(self): ...
-    def get_ext_fullpath(self, ext_name): ...
-    def get_ext_fullname(self, ext_name): ...
-    def get_ext_filename(self, ext_name): ...
+    def get_ext_fullpath(self, ext_name: str) -> str: ...
+    def get_ext_fullname(self, ext_name: str) -> str: ...
+    def get_ext_filename(self, ext_name: str) -> str: ...
     def get_export_symbols(self, ext): ...
     def get_libraries(self, ext): ...
diff --git a/stubs/setuptools/setuptools/_distutils/command/build_ext.pyi b/stubs/setuptools/setuptools/_distutils/command/build_ext.pyi
index bdb3cefeb..dfdfe4427 100644
--- a/stubs/setuptools/setuptools/_distutils/command/build_ext.pyi
+++ b/stubs/setuptools/setuptools/_distutils/command/build_ext.pyi
@@ -39,8 +39,8 @@ class build_ext(Command):
     def build_extension(self, ext) -> None: ...
     def swig_sources(self, sources, extension): ...
     def find_swig(self): ...
-    def get_ext_fullpath(self, ext_name): ...
-    def get_ext_fullname(self, ext_name): ...
-    def get_ext_filename(self, ext_name): ...
+    def get_ext_fullpath(self, ext_name: str) -> str: ...
+    def get_ext_fullname(self, ext_name: str) -> str: ...
+    def get_ext_filename(self, ext_name: str) -> str: ...
     def get_export_symbols(self, ext): ...
     def get_libraries(self, ext): ...