diff --git a/package-lock.json b/package-lock.json
index bb43adcf70..b1288c49a8 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "blockly",
-  "version": "12.0.0",
+  "version": "12.0.0-beta.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "blockly",
-      "version": "12.0.0",
+      "version": "12.0.0-beta.0",
       "hasInstallScript": true,
       "license": "Apache-2.0",
       "dependencies": {
diff --git a/package.json b/package.json
index 9469fc5d32..8e10e21638 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "blockly",
-  "version": "12.0.0",
+  "version": "12.0.0-beta.0",
   "description": "Blockly is a library for building visual programming editors.",
   "keywords": [
     "blockly"