diff --git a/build.cmd b/build.cmd
index 35de1b3568098e2e812f195b8d6c0a6a75cc0b28..f1ff389b677f5f6007b7b7fc91e8d7ab48196bdb 100644
--- a/build.cmd
+++ b/build.cmd
@@ -1,3 +1,4 @@
+.\venv\Scripts\activate
 pip install -r requirements\dev.in --user --force-reinstall --use-pep517 --no-cache-dir --compile --progress-bar pretty --log logfile1.txt
 pip install -e . --user --force-reinstall --use-pep517 --no-cache-dir --compile --progress-bar pretty --log logfile2.txt
 rem pip install -q build --implementation py  --python-version 3.8 --user --force-reinstall --use-pep517 --compile --progress-bar pretty