diff --git a/konova/management/commands/quality_check.py b/konova/management/commands/quality_check.py
index 1100e04..a58bda1 100644
--- a/konova/management/commands/quality_check.py
+++ b/konova/management/commands/quality_check.py
@@ -66,4 +66,4 @@ class Command(BaseKonovaCommand):
                 checker = CheckerClass(entry)
                 checker.run_check()
                 if not checker.valid:
-                    self._write_error(f"{entry.identifier};{';'.join(checker.messages)}")
+                    self._write_error(f"{entry.identifier};{';'.join(str(msg) for msg in checker.messages)}")