diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 565bc506c6d88046fd06a684db9cd75eafdea1bf..6e7abb71b10c5736cc75fe7953e2d908d073f998 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -65,6 +65,9 @@ run_unit_tests_py310:
   image: python:3.10-bullseye
   stage: test
   script:
+    # Debian Bullseye ships with libboost-python linked to Python 3.9. Use the one from Debian Sid instead.
+    - echo 'deb http://deb.debian.org/debian sid main' >> /etc/apt/sources.list
+    - apt-get update -y && DEBIAN_FRONTEND=noninteractive apt-get install -y libboost-python1.74-dev
     - echo "run python3.10 unit tests /w coverage"
     - tox -e py310