diff --git a/theatre/core/package.json b/theatre/core/package.json
index 4f49473..fb1a609 100644
--- a/theatre/core/package.json
+++ b/theatre/core/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@theatre/core",
-  "version": "0.4.0-dev.1",
+  "version": "0.4.0-dev.2",
   "license": "Apache-2.0",
   "description": "Motion design editor for the web",
   "repository": {
@@ -42,4 +42,4 @@
   "dependencies": {
     "@theatre/dataverse": "workspace:*"
   }
-}
+}
\ No newline at end of file
diff --git a/theatre/devEnv/updateVersions.ts b/theatre/devEnv/updateVersions.ts
new file mode 100644
index 0000000..96e2f12
--- /dev/null
+++ b/theatre/devEnv/updateVersions.ts
@@ -0,0 +1,19 @@
+import {writeFileSync} from 'fs'
+import path from 'path'
+
+const theatreDir = path.join(__dirname, '..')
+const version = require('../package.json').version
+
+for (const which of ['core', 'studio']) {
+  const original = require('../' + which + '/package.json')
+  if (original.version !== version) {
+    console.log(`Setting version of @theatre/${which} to ${version}`)
+
+    const newJson = {...original}
+    newJson.version = version
+    writeFileSync(
+      path.join(theatreDir, `./${which}/package.json`),
+      JSON.stringify(newJson, undefined, 2),
+    )
+  }
+}
diff --git a/theatre/package.json b/theatre/package.json
index 43452aa..ea5d4dd 100644
--- a/theatre/package.json
+++ b/theatre/package.json
@@ -1,4 +1,6 @@
 {
+  "private": true,
+  "version": "0.4.0-dev.2",
   "workspaces": [
     "./shared",
     "./core",
@@ -11,7 +13,8 @@
     "build:dts": "run-s typecheck build:dts:bundle",
     "build:dts:bundle": "rollup -c devEnv/declarations-bundler/rollup.config.js",
     "build": "run-p build:dts build:js",
-    "prepare": "run-s build"
+    "prepare": "run-s update-versions build",
+    "update-versions": "node -r esbuild-register devEnv/updateVersions.ts"
   },
   "devDependencies": {
     "@babel/cli": "^7.14.3",
diff --git a/theatre/studio/package.json b/theatre/studio/package.json
index 39e7804..c9dbf53 100644
--- a/theatre/studio/package.json
+++ b/theatre/studio/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@theatre/studio",
-  "version": "0.4.0-dev.1",
+  "version": "0.4.0-dev.2",
   "license": "AGPL-3.0-only",
   "description": "Motion design editor for the web",
   "repository": {
@@ -45,4 +45,4 @@
   "peerDependencies": {
     "@theatre/core": "*"
   }
-}
+}
\ No newline at end of file