diff --git a/.ci/install.sh b/.ci/install.sh
index e85e6bdc575..0e7d9769084 100755
--- a/.ci/install.sh
+++ b/.ci/install.sh
@@ -34,6 +34,7 @@ python3 -m pip install ipython
 python3 -m pip install olefile
 python3 -m pip install -U pytest
 python3 -m pip install -U pytest-cov
+python3 -m pip install -U pytest-freethreaded
 python3 -m pip install -U pytest-timeout
 python3 -m pip install pyroma