diff --git a/lerna.json b/lerna.json
index 89906fd..717fde0 100644
--- a/lerna.json
+++ b/lerna.json
@@ -1,5 +1,5 @@
 {
   "lerna": "2.4.0",
-  "version": "0.9.30",
+  "version": "0.9.31",
   "packages": ["packages/*"]
 }
diff --git a/scripts/bump-version.js b/scripts/bump-version.js
index 89a31c3..646027e 100644
--- a/scripts/bump-version.js
+++ b/scripts/bump-version.js
@@ -13,10 +13,10 @@ lernaJson.version = newVersion;
 fs.writeFileSync('./lerna.json', JSON.stringify(lernaJson, null, 4), 'utf8');
 
 [
-    [mobxDevtools, './packages/mobx-devtools/package.json'],
-    [mobxDevtoolsMst, './packages/mobx-devtools-mst/package.json'],
-    [playground, './packages/playground/package.json'],
+  [mobxDevtools, './packages/mobx-devtools/package.json'],
+  [mobxDevtoolsMst, './packages/mobx-devtools-mst/package.json'],
+  [playground, './packages/playground/package.json'],
 ].forEach(([pkg, path]) => {
-    pkg.version = newVersion;
-    fs.writeFileSync(path, JSON.stringify(pkg, null, 4), 'utf8');
+  pkg.version = newVersion;
+  fs.writeFileSync(path, JSON.stringify(pkg, null, 4), 'utf8');
 });