diff --git a/ospec/package.json b/ospec/package.json
index d62823292..5c395ebeb 100644
--- a/ospec/package.json
+++ b/ospec/package.json
@@ -3,7 +3,6 @@
   "version": "3.0.1",
   "description": "Noiseless testing framework",
   "main": "ospec.js",
-  "module": "ospec.mjs",
   "directories": {
     "test": "tests"
   },
diff --git a/package.json b/package.json
index f856f7bae..2e1bc9be4 100644
--- a/package.json
+++ b/package.json
@@ -5,7 +5,6 @@
   "author": "Leo Horie",
   "license": "MIT",
   "main": "mithril.js",
-  "module": "mithril.mjs",
   "repository": "MithrilJS/mithril.js",
   "scripts": {
     "dev": "node bundler/cli browser.js -output mithril.js -watch",
diff --git a/stream/package.json b/stream/package.json
index d78616b68..f5f4f86cd 100644
--- a/stream/package.json
+++ b/stream/package.json
@@ -3,7 +3,6 @@
   "version": "1.1.0",
   "description": "Streaming data, mithril-style",
   "main": "stream.js",
-  "module": "stream.mjs",
   "directories": {
     "test": "tests"
   },