diff --git a/optuna_dashboard/static/components/GraphSlice.tsx b/optuna_dashboard/static/components/GraphSlice.tsx
index cb4bd055..91534c7b 100644
--- a/optuna_dashboard/static/components/GraphSlice.tsx
+++ b/optuna_dashboard/static/components/GraphSlice.tsx
@@ -26,6 +26,7 @@ const useStyles = makeStyles((theme: Theme) =>
   })
 )
 
+// TODO(c-bata): Check `log` field of IntDistribution and FloatDistribution.
 const logDistributions = ["LogUniformDistribution", "IntLogUniformDistribution"]
 
 export const GraphSlice: FC<{