diff --git a/composer.json b/composer.json
index aaae951..c083036 100644
--- a/composer.json
+++ b/composer.json
@@ -25,6 +25,6 @@
     "proprietary"
   ],
   "require": {
-    "d3/importer": "^5.0"
+    "d3/importer": "^5.0|^6"
   }
 }