diff --git a/misc/python/materialize/mzcompose/__init__.py b/misc/python/materialize/mzcompose/__init__.py
index 257a882294587..5b4a708b6c689 100644
--- a/misc/python/materialize/mzcompose/__init__.py
+++ b/misc/python/materialize/mzcompose/__init__.py
@@ -354,10 +354,10 @@ def get_variable_system_parameters(
             "persist_blob_cache_scale_with_threads", "true", ["true", "false"]
         ),
         VariableSystemParameter(
-            "persist_validate_part_bounds_on_read", "true", ["true", "false"]
+            "persist_validate_part_bounds_on_read", "false", ["true", "false"]
         ),
         VariableSystemParameter(
-            "persist_validate_part_bounds_on_write", "true", ["true", "false"]
+            "persist_validate_part_bounds_on_write", "false", ["true", "false"]
         ),
         VariableSystemParameter("pg_offset_known_interval", "1s", ["100ms", "1s"]),
         VariableSystemParameter(