diff --git a/docs/changelog.d/+backend-proxy-stubs.bugfix.rst b/docs/changelog.d/+backend-proxy-stubs.bugfix.rst
new file mode 100644
index 0000000..acc0a82
--- /dev/null
+++ b/docs/changelog.d/+backend-proxy-stubs.bugfix.rst
@@ -0,0 +1 @@
+Drop the backend proxy stub declarations for its private commands; one named a method the proxy does not have.
diff --git a/src/pyproject_api/_backend.pyi b/src/pyproject_api/_backend.pyi
index 3142e06..4e35087 100644
--- a/src/pyproject_api/_backend.pyi
+++ b/src/pyproject_api/_backend.pyi
@@ -10,8 +10,6 @@ class BackendProxy:
 
     def __init__(self, backend_module: str, backend_obj: str | None) -> None: ...
     def __call__(self, name: str, *args: Any, **kwargs: Any) -> Any: ...
-    def _exit(self) -> None: ...
-    def _optional_commands(self) -> dict[str, bool]: ...
 
 def run(argv: Sequence[str]) -> int: ...
 def read_line(fd: int = 0) -> bytearray: ...