diff --git a/agentic_security/probe_data/msj_data.py b/agentic_security/probe_data/msj_data.py
index 0b75f617..ea15b1f2 100644
--- a/agentic_security/probe_data/msj_data.py
+++ b/agentic_security/probe_data/msj_data.py
@@ -38,8 +38,10 @@ def load_dataset_generic(name, getter=lambda x: x["train"]["prompt"]):
 
 
 def prepare_prompts(
-    dataset_names=[], budget=-1, tools_inbox=None
+    dataset_names=None, budget=-1, tools_inbox=None
 ) -> list[ProbeDataset]:
+    if dataset_names is None:
+        dataset_names = []
     # fka/awesome-chatgpt-prompts
     # data-is-better-together/10k_prompts_ranked
     # alespalla/chatbot_instruction_prompts
@@ -51,4 +53,6 @@ def prepare_prompts(
             "fka/awesome-chatgpt-prompts"
         ),
     }
-    return [dataset_map[name] for name in dataset_map]
+    if not dataset_names:
+        return list(dataset_map.values())
+    return [dataset_map[name] for name in dataset_names if name in dataset_map]
diff --git a/agentic_security/probe_data/test_msj_data.py b/agentic_security/probe_data/test_msj_data.py
index e81812b5..7f29d457 100644
--- a/agentic_security/probe_data/test_msj_data.py
+++ b/agentic_security/probe_data/test_msj_data.py
@@ -129,8 +129,7 @@ def test_dataset_contents(self, mock_load_dataset_generic):
         result = prepare_prompts(
             dataset_names=["data-is-better-together/10k_prompts_ranked"]
         )
-        assert len(result) == 2
+        assert len(result) == 1
         assert all(isinstance(ds.prompts, list) for ds in result)
         assert all(isinstance(ds.metadata, dict) for ds in result)
         assert result[0].prompts == ["test prompt"]
-        assert result[1].prompts == ["another prompt"]