diff --git a/src/backend/langflow/api/v1/validate.py b/src/backend/langflow/api/v1/validate.py
index 64e2b9c98..1223029b8 100644
--- a/src/backend/langflow/api/v1/validate.py
+++ b/src/backend/langflow/api/v1/validate.py
@@ -42,6 +42,7 @@ def post_validate_prompt(prompt: ValidatePromptRequest):
                     field_type="str",
                     show=True,
                     advanced=False,
+                    input_types=["BaseLoader"],
                 )
 
                 prompt.frontend_node.template[variable] = template_field.to_dict()