diff --git a/src/index.js b/src/index.js
index dfb566329..12bb69ee5 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,3 +1,10 @@
 const VirtualMachine = require('./virtual-machine');
 
+const ArgumentType = require('./extension-support/argument-type');
+const BlockType = require('./extension-support/block-type');
+
 module.exports = VirtualMachine;
+
+// TODO: ESM named exports will save us all
+module.exports.ArgumentType = ArgumentType;
+module.exports.BlockType = BlockType;