diff --git a/.github/workflows/build_wheels.yml b/.github/workflows/build_wheels.yml
index 45570d4..ba4e3eb 100644
--- a/.github/workflows/build_wheels.yml
+++ b/.github/workflows/build_wheels.yml
@@ -28,6 +28,7 @@ jobs:
         run: |
           pip install wheel
           pip install setuptools
+          pip install build
 
       - name: build
         run: python -m build
@@ -63,6 +64,7 @@ jobs:
         run: |
           pip install wheel
           pip install setuptools
+          pip install build
 
       - name: build
         run: python -m build
diff --git a/setup.cfg b/setup.cfg
index 4ae30a9..64c220c 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = pywincalc
-version = 3.6.7
+version = 3.6.8
 description = A Python library for calculating thermal and optical properties of glazing systems
 long_description = file: README.md
 long_description_content_type = text/markdown; charset=UTF-8