diff --git a/NEWS b/NEWS
index 20defc5b..028e18a8 100644
--- a/NEWS
+++ b/NEWS
@@ -8,6 +8,9 @@ NEXT
 
 Improvements
 ------------
+* Clear ``force_failure`` in ``_reset()`` so that re-running a test
+  after an ``expectThat`` failure can succeed if successful conditions are met again.
+  (OumarCamara, #563)
 
 * Make ``extract_result()`` and ``DeferredNotFired`` public APIs in
   ``testtools.twistedsupport``. These utilities are useful for extracting
diff --git a/testtools/testcase.py b/testtools/testcase.py
index 3f14011a..334bc2b9 100644
--- a/testtools/testcase.py
+++ b/testtools/testcase.py
@@ -307,6 +307,9 @@ def _reset(self) -> None:
         # __details is lazy-initialized so that a constructed-but-not-run
         # TestCase is safe to use with clone_test_with_new_id.
         self.__details: DetailsDict | None = None
+        # force_failure is set by expectThat() on mismatch; must be
+        # cleared so re-runs of the same test can succeed.
+        self.force_failure: bool | None = None
 
     def __eq__(self, other: object) -> bool:
         eq = getattr(unittest.TestCase, "__eq__", None)