diff --git a/tests/primitives/test_block.py b/tests/primitives/test_block.py
index 9059a88..0407b0f 100644
--- a/tests/primitives/test_block.py
+++ b/tests/primitives/test_block.py
@@ -58,4 +58,4 @@
         cipher._operation = pretend.stub(name="wat")
 
         with pytest.raises(ValueError):
-            cipher.encrypt(b"b" * 16)
+            cipher.finalize()