diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index c1e46143c..210f1d8c4 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -29,12 +29,12 @@ jobs:
           cd ..
           git clone -b feature/airflow2.6.3 https://github.com/The-Academic-Observatory/observatory-platform.git
           cd observatory-platform
-          pip install -e observatory-api
-          pip install -e observatory-platform
+          pip install -e observatory-api --user --constraint https://raw.githubusercontent.com/apache/airflow/constraints-2.6.3/constraints-no-providers-3.8.txt
+          pip install -e observatory-platform --user --constraint https://raw.githubusercontent.com/apache/airflow/constraints-2.6.3/constraints-no-providers-3.8.txt
           cd ..
 
           cd academic-observatory-workflows
-          pip install -e .[tests]
+          pip install -e .[tests] --user --constraint https://raw.githubusercontent.com/apache/airflow/constraints-2.6.3/constraints-no-providers-3.8.txt
 
       - name: Check licenses
         run: |