diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index d83199d..993b68e 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -42,7 +42,7 @@ jobs:
     - name: install dependencies
       run: |
         python3 -m pip install wheel setuptools pytest
-        python3 -m pip -vvv install .
+        python3 -m pip -vvv install --no-use-pep517 .
 
     - name: install Unix dependencies
       if: matrix.os != 'windows-latest'