diff --git a/src/_pytest/unittest.py b/src/_pytest/unittest.py
index a05c3b4bc43..ac5a3a3fd5e 100644
--- a/src/_pytest/unittest.py
+++ b/src/_pytest/unittest.py
@@ -189,7 +189,7 @@ def setup(self) -> None:
         # A bound method to be called during teardown() if set (see 'runtest()').
         self._explicit_tearDown: Optional[Callable[[], None]] = None
         assert self.parent is not None
-        self._testcase = self.parent.obj(self.name)  # type: ignore[attr-defined]
+        self._testcase = self.parent.obj(self.name or 'runTest')  # type: ignore[attr-defined]
         self._obj = getattr(self._testcase, self.name)
         if hasattr(self, "_request"):
             self._request._fillfixtures()