diff --git a/autoninja.bat b/autoninja.bat
index 34b477e71..14e2f4597 100755
--- a/autoninja.bat
+++ b/autoninja.bat
@@ -8,7 +8,7 @@ setlocal
 set scriptdir=%~dp0
 
 REM Set unique build ID.
-FOR /f "usebackq tokens=*" %%a in (`python -c "import uuid; print(uuid.uuid4())"`) do set AUTONINJA_BUILD_ID=%%a
+FOR /f "usebackq tokens=*" %%a in (`%scriptdir%python-bin\python3.bat -c "import uuid; print(uuid.uuid4())"`) do set AUTONINJA_BUILD_ID=%%a
 
 REM If a build performance summary has been requested then also set NINJA_STATUS
 REM to trigger more verbose status updates. In particular this makes it possible
@@ -37,17 +37,17 @@ REM Don't use vpython - it is too slow to start.
 REM Don't use python3 because it doesn't work in git bash on Windows and we
 REM should be consistent between autoninja.bat and the autoninja script used by
 REM git bash.
-FOR /f "usebackq tokens=*" %%a in (`python %scriptdir%autoninja.py "%*"`) do echo %%a & %%a
+FOR /f "usebackq tokens=*" %%a in (`%scriptdir%python-bin\python3.bat %scriptdir%autoninja.py "%*"`) do echo %%a & %%a
 @if errorlevel 1 goto buildfailure
 
-REM Use call to invoke python script here, because we use python via python.bat.
-@if "%NINJA_SUMMARIZE_BUILD%" == "1" call python %scriptdir%post_build_ninja_summary.py %*
-@call python %scriptdir%ninjalog_uploader_wrapper.py --cmdline %*
+REM Use call to invoke python script here, because we use python via python3.bat.
+@if "%NINJA_SUMMARIZE_BUILD%" == "1" call %scriptdir%python-bin\python3.bat %scriptdir%post_build_ninja_summary.py %*
+@call %scriptdir%python-bin\python3.bat %scriptdir%ninjalog_uploader_wrapper.py --cmdline %*
 
 exit /b
 :buildfailure
 
-@call python %scriptdir%ninjalog_uploader_wrapper.py --cmdline %*
+@call %scriptdir%python-bin\python3.bat %scriptdir%ninjalog_uploader_wrapper.py --cmdline %*
 
 REM Return an error code of 1 so that if a developer types:
 REM "autoninja chrome && chrome" then chrome won't run if the build fails.