diff --git a/slixmpp_omemo/__init__.py b/slixmpp_omemo/__init__.py
index 6521c3e..0c62e1d 100644
--- a/slixmpp_omemo/__init__.py
+++ b/slixmpp_omemo/__init__.py
@@ -592,8 +592,8 @@ class XEP_0384(BasePlugin):
                     expect_problems=expect_problems,
                 )
                 return _generate_encrypted_payload(encrypted)
-            except omemo.exceptions.EncryptionProblemsException as exn:
-                errors = exn.problems
+            except omemo.exceptions.EncryptionProblemsException as exception:
+                errors = exception.problems
 
             if errors == old_errors:
                 raise EncryptionPrepareException(errors)