diff --git a/package.json b/package.json
index d0590b3..a5e9fca 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "d3-interpolate",
-  "version": "1.3.3",
+  "version": "1.4.0",
   "description": "Interpolate numbers, colors, strings, arrays, objects, whatever!",
   "keywords": [
     "d3",