diff --git a/config/prepareDist.js b/config/prepareDist.js
index 5d35465337e..e58cd77c941 100644
--- a/config/prepareDist.js
+++ b/config/prepareDist.js
@@ -23,6 +23,12 @@ const distRoot = `${__dirname}/../dist`;
 const packageJson = require('../package.json');
 const entryPoints = require('./entryPoints.js');
 
+// Enable default interpretation of .js files as ECMAScript modules. We don't
+// put this in the source ../package.json file because it interferes with tools
+// like ts-node, which we use to run various ../config/*.ts scripts.
+// TODO(benjamn) Fully diagnose that interference.
+packageJson.type = 'module';
+
 // The root package.json is marked as private to prevent publishing
 // from happening in the root of the project. This sets the package back to
 // public so it can be published from the "dist" directory.