diff --git a/src/gflownet/tasks/seh_frag.py b/src/gflownet/tasks/seh_frag.py
index b5ce6075..3d76c4a6 100644
--- a/src/gflownet/tasks/seh_frag.py
+++ b/src/gflownet/tasks/seh_frag.py
@@ -193,7 +193,7 @@ def main():
         "overwrite_existing_exp": True,
         "num_training_steps": 100,
         "num_workers": 8,
-        "mp_buffer_size": None,# 32 * 1024 ** 2,
+        "mp_buffer_size": 32 * 1024 ** 2,
         "opt": {
             "lr_decay": 20000,
         },