diff --git a/README.rst b/README.rst
index 00c6b2f5..5dbd7fe7 100644
--- a/README.rst
+++ b/README.rst
@@ -259,8 +259,7 @@ without having to resort to heuristics.
 The file contains a JSON map. This map has the following keys:
 
 version
-   Version number of the file format. Currently ``0`` until semantics are
-   stabilized.
+   Version number of the file format. Currently ``1``.
 
 os
    Target operating system for the distribution. e.g. ``linux``, ``macos``,
diff --git a/cpython-linux/build.py b/cpython-linux/build.py
index 97b88701..0774da3f 100755
--- a/cpython-linux/build.py
+++ b/cpython-linux/build.py
@@ -651,8 +651,7 @@ def build_cpython(client, image, platform, optimized=False):
 
         # Create PYTHON.json file describing this distribution.
         python_info = {
-            # TODO bump version number once format is somewhat stable.
-            'version': '0',
+            'version': '1',
             'os': 'linux',
             'arch': 'x86_64',
             'python_flavor': 'cpython',
diff --git a/cpython-macos/build.py b/cpython-macos/build.py
index d8b4beac..d9ba48b9 100755
--- a/cpython-macos/build.py
+++ b/cpython-macos/build.py
@@ -365,8 +365,7 @@ def build_cpython(optimized=False):
 
         # Create PYTHON.json file describing this distribution.
         python_info = {
-            # TODO bump version number once format is somewhat stable.
-            'version': '0',
+            'version': '1',
             'os': 'macos',
             'arch': 'x86_64',
             'python_flavor': 'cpython',
diff --git a/cpython-windows/build.py b/cpython-windows/build.py
index 65391bf1..2eb48f69 100644
--- a/cpython-windows/build.py
+++ b/cpython-windows/build.py
@@ -1363,8 +1363,7 @@ def build_cpython(pgo=False):
 
         # Create PYTHON.json file describing this distribution.
         python_info = {
-            # TODO bump version number once format is somewhat stable.
-            'version': '0',
+            'version': '1',
             'os': 'windows',
             'arch': 'x86_64',
             'python_flavor': 'cpython',