diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 1b7bc500081c59fe7a110021c344aa2399eb9099..005965928a6579c38613dc44afba9fdc0b121faf 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -68,7 +68,7 @@ test_maxima:
   parallel:
     matrix:
       - TEST_VERSION: "2023052400"
-        QSTACK_VERSION: "master"
+        QSTACK_VERSION: "v4.4.3"
         MOODLE_BRANCH: "MOODLE_39_STABLE"
       - TEST_VERSION: "2023010400"
         QSTACK_VERSION: "v4.4.2"