diff --git a/CHANGELOG.md b/CHANGELOG.md
index cdeeceeef..b77eb5a84 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,10 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [2.0.0-pre.6](https://github.com/vivliostyle/vivliostyle/compare/v2.0.0-pre.5...v2.0.0-pre.6) (2019-12-23)
+
+**Note:** Version bump only for package vivliostyle
+
 # [2.0.0-pre.5](https://github.com/vivliostyle/vivliostyle/compare/v2.0.0-pre.4...v2.0.0-pre.5) (2019-12-23)
 
 ### Bug Fixes
diff --git a/lerna.json b/lerna.json
index 2c309e510..c60ba6fad 100644
--- a/lerna.json
+++ b/lerna.json
@@ -4,6 +4,6 @@
   ],
   "useWorkspaces": true,
   "npmClient": "yarn",
-  "version": "2.0.0-pre.5",
+  "version": "2.0.0-pre.6",
   "includeMergedTags": true
 }
diff --git a/packages/core/CHANGELOG.md b/packages/core/CHANGELOG.md
index b13781d3b..cb1037ede 100644
--- a/packages/core/CHANGELOG.md
+++ b/packages/core/CHANGELOG.md
@@ -3,6 +3,10 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [2.0.0-pre.6](https://github.com/vivliostyle/vivliostyle/compare/v2.0.0-pre.5...v2.0.0-pre.6) (2019-12-23)
+
+**Note:** Version bump only for package @vivliostyle/core
+
 # [2.0.0-pre.5](https://github.com/vivliostyle/vivliostyle/compare/v2.0.0-pre.4...v2.0.0-pre.5) (2019-12-23)
 
 ### Bug Fixes
diff --git a/packages/core/package.json b/packages/core/package.json
index c59f076b5..8d9de2ec7 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@vivliostyle/core",
   "description": "Library for HTML+CSS typesetting and rich paged viewing with EPUB/Web publications support.",
-  "version": "2.0.0-pre.5",
+  "version": "2.0.0-pre.6",
   "scripts": {
     "build": "NODE_ENV=production rollup -c",
     "build-dev": "NODE_ENV=development rollup -c",
diff --git a/packages/viewer/CHANGELOG.md b/packages/viewer/CHANGELOG.md
index 2d3ed2e17..8b4587dae 100644
--- a/packages/viewer/CHANGELOG.md
+++ b/packages/viewer/CHANGELOG.md
@@ -3,6 +3,10 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [2.0.0-pre.6](https://github.com/vivliostyle/vivliostyle/compare/v2.0.0-pre.5...v2.0.0-pre.6) (2019-12-23)
+
+**Note:** Version bump only for package @vivliostyle/viewer
+
 # [2.0.0-pre.5](https://github.com/vivliostyle/vivliostyle/compare/v2.0.0-pre.4...v2.0.0-pre.5) (2019-12-23)
 
 ### Bug Fixes
diff --git a/packages/viewer/package.json b/packages/viewer/package.json
index 78d6c6750..cbe93d68c 100644
--- a/packages/viewer/package.json
+++ b/packages/viewer/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@vivliostyle/viewer",
   "description": "Vivliostyle Viewer UI component, for rich paged viewing and printing in browser.",
-  "version": "2.0.0-pre.5",
+  "version": "2.0.0-pre.6",
   "scripts": {
     "build": "gulp build && NODE_ENV=production rollup -c",
     "build-dev": "gulp build-dev && NODE_ENV=development rollup -c",
@@ -18,7 +18,7 @@
     "test-sauce": "echo 'Tests for Vivliostyle Viewer has been disabled. See #618.'"
   },
   "dependencies": {
-    "@vivliostyle/core": "^2.0.0-pre.5"
+    "@vivliostyle/core": "^2.0.0-pre.6"
   },
   "devDependencies": {
     "@babel/core": "^7.7.7",