diff --git a/kcidb_io/schema/misc.py b/kcidb_io/schema/misc.py
index 4f57e69..55198b1 100644
--- a/kcidb_io/schema/misc.py
+++ b/kcidb_io/schema/misc.py
@@ -218,7 +218,6 @@ def upgrade(self, data, copy=True):
                                                    or any of the previous
                                                    schema versions.
         """
-        assert LIGHT_ASSERTS or self.is_valid(data)
         if copy:
             data = deepcopy(data)
         if not self.is_compatible_exactly(data):