diff --git a/src/instructlab/schema/taxonomy.py b/src/instructlab/schema/taxonomy.py
index a3e9e14..cc00724 100644
--- a/src/instructlab/schema/taxonomy.py
+++ b/src/instructlab/schema/taxonomy.py
@@ -264,6 +264,8 @@ def _yamllint(self, text: str, taxonomy: Taxonomy) -> None:
                 stdout=subprocess.PIPE,
                 stderr=subprocess.STDOUT,
             )
+            if "invalid config" in result.stdout:
+                logger.warning(f"Invalid custom rules: {result.stdout}")
         except FileNotFoundError:
             logger.warning(
                 "could not run yamllint command",