diff --git a/.readthedocs.yml b/.readthedocs.yml
index adf253dce..d2c0c9431 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -8,6 +8,10 @@ version: 2
 sphinx:
   configuration: docs/conf.py
 
+formats:
+  - htmlzip
+  # we can't build epub / pdf
+
 python:
   install:
     - requirements: docs/requirements-doc.txt
diff --git a/Makefile.envs b/Makefile.envs
index fab57fad6..87732a642 100644
--- a/Makefile.envs
+++ b/Makefile.envs
@@ -1,6 +1,6 @@
 export PYVERSION ?= 3.12.1
 export PYODIDE_EMSCRIPTEN_VERSION ?= 3.1.58
-export PYODIDE_VERSION ?= 0.26.0
+export PYODIDE_VERSION ?= 0.27.0.dev0
 export PYODIDE_ABI_VERSION ?= 2024_0
 
 export PYTHON_ARCHIVE_SHA256=d01ec6a33bc10009b09c17da95cc2759af5a580a7316b3a446eb4190e13f97b2
diff --git a/pyodide-build/pyodide_build/__init__.py b/pyodide-build/pyodide_build/__init__.py
index 7c4a9591e..ea14a2ed7 100644
--- a/pyodide-build/pyodide_build/__init__.py
+++ b/pyodide-build/pyodide_build/__init__.py
@@ -1 +1 @@
-__version__ = "0.26.0"
+__version__ = "0.27.0.dev0"
diff --git a/src/core/pre.js b/src/core/pre.js
index 28b1a5b46..b6fec7a63 100644
--- a/src/core/pre.js
+++ b/src/core/pre.js
@@ -2,7 +2,7 @@ const API = Module.API;
 const Hiwire = {};
 const Tests = {};
 API.tests = Tests;
-API.version = "0.26.0";
+API.version = "0.27.0.dev0";
 Module.hiwire = Hiwire;
 
 function getTypeTag(x) {
diff --git a/src/js/package-lock.json b/src/js/package-lock.json
index 5c83f4448..04187db18 100644
--- a/src/js/package-lock.json
+++ b/src/js/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "pyodide",
-  "version": "0.26.0",
+  "version": "0.27.0-dev.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "pyodide",
-      "version": "0.26.0",
+      "version": "0.27.0-dev.0",
       "license": "Apache-2.0",
       "dependencies": {
         "ws": "^8.5.0"
diff --git a/src/js/package.json b/src/js/package.json
index dc80ce983..a1c966b33 100644
--- a/src/js/package.json
+++ b/src/js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "pyodide",
-  "version": "0.26.0",
+  "version": "0.27.0-dev.0",
   "description": "The Pyodide JavaScript package",
   "keywords": [
     "python",
diff --git a/src/js/version.ts b/src/js/version.ts
index 7a7ce8875..3cc644bfe 100644
--- a/src/js/version.ts
+++ b/src/js/version.ts
@@ -6,4 +6,4 @@
  * from the version in ``package.json`` which follows the node package manager
  * version convention.
  */
-export const version: string = "0.26.0";
+export const version: string = "0.27.0.dev0";
diff --git a/src/py/pyodide/__init__.py b/src/py/pyodide/__init__.py
index cfc12af9d..541d875a1 100644
--- a/src/py/pyodide/__init__.py
+++ b/src/py/pyodide/__init__.py
@@ -10,7 +10,7 @@
 # This package is imported by the test suite as well, and currently we don't use
 # pytest mocks for js or pyodide_js, so make sure to test "if IN_BROWSER" before
 # importing from these.
-__version__ = "0.26.0"
+__version__ = "0.27.0.dev0"
 
 __all__ = ["__version__", "console", "code", "ffi", "http", "webloop"]
 
diff --git a/src/py/pyproject.toml b/src/py/pyproject.toml
index 856fb128f..dc648fc72 100644
--- a/src/py/pyproject.toml
+++ b/src/py/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "pyodide-py"
-version = "0.26.0"
+version = "0.27.0.dev0"
 authors = [{name = "Pyodide developers"}]
 description = "A Python package providing core interpreter functionality for Pyodide"
 classifiers = [