diff --git a/optuna_dashboard/_importance.py b/optuna_dashboard/_importance.py
index 56d26716..401310ab 100644
--- a/optuna_dashboard/_importance.py
+++ b/optuna_dashboard/_importance.py
@@ -19,7 +19,7 @@ except ImportError:
 
 try:
     from optuna_fast_fanova import FanovaImportanceEvaluator as FastFanovaImportanceEvaluator
-except ImportError:
+except (ImportError, ValueError):
     FastFanovaImportanceEvaluator = None  # type: ignore