diff --git a/src/plaid/storage/cgns/writer.py b/src/plaid/storage/cgns/writer.py
index 5f98d0e3..2f466a12 100644
--- a/src/plaid/storage/cgns/writer.py
+++ b/src/plaid/storage/cgns/writer.py
@@ -327,7 +327,7 @@ def configure_dataset_card(
 pb_defs = load_problem_definitions_from_hub(repo_id)
 
 
-pb_def = pb_defs[0]
+pb_def = next(iter(pb_defs.values()))
 
 plaid_sample = ... # use a method from above to instantiate a plaid sample
 
diff --git a/src/plaid/storage/hf_datasets/writer.py b/src/plaid/storage/hf_datasets/writer.py
index 3a98147b..77276c2b 100644
--- a/src/plaid/storage/hf_datasets/writer.py
+++ b/src/plaid/storage/hf_datasets/writer.py
@@ -327,7 +327,7 @@ def configure_dataset_card(
 pb_defs = load_problem_definitions_from_hub(repo_id)
 
 
-pb_def = pb_defs[0]
+pb_def = next(iter(pb_defs.values()))
 
 plaid_sample = ... # use a method from above to instantiate a plaid sample
 
diff --git a/src/plaid/storage/zarr/writer.py b/src/plaid/storage/zarr/writer.py
index 71408523..004dc5ac 100644
--- a/src/plaid/storage/zarr/writer.py
+++ b/src/plaid/storage/zarr/writer.py
@@ -463,7 +463,7 @@ def configure_dataset_card(
 pb_defs = load_problem_definitions_from_hub(repo_id)
 
 
-pb_def = pb_defs[0]
+pb_def = next(iter(pb_defs.values()))
 
 plaid_sample = ... # use a method from above to instantiate a plaid sample