diff --git a/ward/expect.py b/ward/expect.py
index 47d3f7ff..8d53cfd4 100644
--- a/ward/expect.py
+++ b/ward/expect.py
@@ -38,7 +38,7 @@ def __exit__(
         exc_val: Optional[BaseException],
         exc_tb: Optional[types.TracebackType],
     ) -> bool:
-        if not issubclass(exc_type, self.expected_ex_type):
+        if exc_type and not issubclass(exc_type, self.expected_ex_type):
             raise AssertionError(
                 f"Expected exception {self.expected_ex_type}, but {exc_type} was raised instead."
             )