diff --git a/index.ts b/index.ts
index 707304d..34b04c9 100644
--- a/index.ts
+++ b/index.ts
@@ -7,7 +7,8 @@ export {
   HistogramGenerator,
   Numeric,
   Primitive,
-  ThresholdArrayGenerator,
+  ThresholdNumberArrayGenerator,
+  ThresholdDateArrayGenerator,
   ThresholdCountGenerator,
   // d3-axis
   Axis,