diff --git a/packages/browser-stdenv/package.json b/packages/browser-stdenv/package.json
index 9fb7a42..3a8ce6a 100644
--- a/packages/browser-stdenv/package.json
+++ b/packages/browser-stdenv/package.json
@@ -15,7 +15,7 @@
   "author": "Tony Garnock-Jones <tonyg@leastfixedpoint.com>",
   "scripts": {
     "prepare": "./build-aggregate.sh",
-    "clean": "rm -rf index.js index.min.js",
+    "clean": "rm -rf index.js index.min.js *.js.map",
     "veryclean": "yarn run clean && rm -rf node_modules"
   },
   "dependencies": {
diff --git a/packages/core/package.json b/packages/core/package.json
index c817faa..0fc5934 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -21,7 +21,7 @@
     "rollup:watch": "../../node_modules/.bin/rollup -c -w",
     "test": "../../node_modules/.bin/jest",
     "cover": "../../node_modules/.bin/nyc --reporter=html ../../node_modules/.bin/jest",
-    "clean": "rm -rf lib dist",
+    "clean": "rm -rf lib dist ./src/gen",
     "veryclean": "yarn run clean && rm -rf node_modules"
   },
   "main": "dist/syndicate.js",