diff --git a/Makefile b/Makefile
index 1f2f904..f7bbae2 100644
--- a/Makefile
+++ b/Makefile
@@ -1,18 +1,23 @@
 # This Makefile is a wrapper around the scripts from `package.json`.
 # https://github.com/lgarron/Makefile-scripts
+# Run `make first-run` once to set up the commands. # this-line-will-be-deleted-during-first-run
+.PHONY: first-run # this-line-will-be-deleted-during-first-run
+first-run: update-Makefile # this-line-will-be-deleted-during-first-run
 
 # Note: the first command becomes the default `make` target.
-NPM_COMMANDS = build build-main build-types build-extended build-extended-types build-browser-global build-bin build-demo build-inspector dev dev-inspector clean test setup lint format prepack postpublish
+NPM_COMMANDS = build build-js build-types build-bin build-demo build-inspector dev dev-inspector clean test setup lint format prepack postpublish
 
 .PHONY: $(NPM_COMMANDS)
 $(NPM_COMMANDS):
 	npm run $@
 
 # We write the npm commands to the top of the file above to make shell autocompletion work in more places.
-DYNAMIC_NPM_COMMANDS = $(shell cat package.json | npx jq --raw-output ".scripts | keys_unsorted | join(\" \")")
+DYNAMIC_NPM_COMMANDS = $(shell node -e 'console.log(Object.keys(require("./package.json").scripts).join(" "))')
+UPDATE_MAKEFILE_SED_ARGS = "s/^NPM_COMMANDS = .*$$/NPM_COMMANDS = ${DYNAMIC_NPM_COMMANDS}/" Makefile
 .PHONY: update-Makefile
 update-Makefile:
-	sed -i "" "s/^NPM_COMMANDS = .*$$/NPM_COMMANDS = ${DYNAMIC_NPM_COMMANDS}/" Makefile
+	if [ "$(shell uname -s)" = "Darwin" ] ; then sed -i "" ${UPDATE_MAKEFILE_SED_ARGS} ; fi
+	if [ "$(shell uname -s)" != "Darwin" ] ; then sed -i"" ${UPDATE_MAKEFILE_SED_ARGS} ; fi
 
 .PHONY: publish
 publish:
diff --git a/package.json b/package.json
index 3257a97..535ffb2 100644
--- a/package.json
+++ b/package.json
@@ -33,12 +33,9 @@
     "typescript": "^3.9.7"
   },
   "scripts": {
-    "build": "npm run build-main && npm run build-types && npm run build-extended && npm run build-extended-types && npm run build-browser-global && npm run build-bin && npm run build-demo",
-    "build-main": "npx parcel build --target main src/targets/main.ts",
+    "build": "npm run build-js",
+    "build-js": "node script/build.js",
     "build-types": "npx parcel build --target types src/targets/main.types.ts",
-    "build-extended": "npx parcel build --target extended src/targets/extended.ts",
-    "build-extended-types": "npx parcel build --target extended-types src/targets/extended.types.ts",
-    "build-browser-global": "npx parcel build --target browser-global src/targets/browser-global.ts",
     "build-bin": "npx parcel build --target bin src/targets/bin.ts && make format-bin",
     "build-demo": "npx parcel build --public-url . --target demo src/targets/demo/index.html",
     "build-inspector": "npx parcel build --target inspector src/targets/inspector/inspector.ts",