diff --git a/.github/workflows/ci-tests.yml b/.github/workflows/ci-tests.yml
index 01eb8232..88de09a1 100644
--- a/.github/workflows/ci-tests.yml
+++ b/.github/workflows/ci-tests.yml
@@ -99,6 +99,7 @@ jobs:
             - name: PHP unit tests
               run: phpunit ./
               working-directory: Nominatim/test/php
+              if: matrix.ubuntu == 20
 
             - name: Python unit tests
               run: $PYTEST test/python