diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 91fd8fdf89de84e37d945e3d926b71303e94a300..cd3e46b535e6f81438acdd4b4c649cdbaa71e215 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -138,7 +138,7 @@ unittest_py3.9:
   tags: [cached-dind]
   stage: test
   variables:
-    PYVER: 3.9
+    PYVER: "3.9"
   image: python:3.9
   script: &python_test_script
     # install dependencies
@@ -147,15 +147,15 @@ unittest_py3.9:
     - pip install git+https://gitlab.indiscale.com/caosdb/src/caosdb-pylib.git@${PYLIB}
     - pip install git+https://gitlab.indiscale.com/caosdb/src/caosdb-advanced-user-tools.git@${ADVANCED}
     - pip install .[h5-crawler,spss,rocrate]
-    - echo "import sys; assert sys.version.startswith('"$PYVER"')"
-    - python3 -c "import sys; assert sys.version.startswith('"$PYVER"')"
+    - echo "import sys; assert sys.version.startswith('$PYVER')"
+    - python3 -c "import sys; assert sys.version.startswith('$PYVER')"
     # actual test
     - caosdb-crawler --help
     - pytest --cov=caosdb -vv ./unittests
 
 unittest_py3.10:
   variables:
-    PYVER: 3.10
+    PYVER: "3.10"
   stage: test
   tags: [cached-dind]
   image: python:3.10
@@ -163,7 +163,7 @@ unittest_py3.10:
 
 unittest_py3.11:
   variables:
-    PYVER: 3.9
+    PYVER: "3.11"
   tags: [cached-dind]
   stage: test
   image: python:3.11
@@ -171,7 +171,7 @@ unittest_py3.11:
 
 unittest_py3.12:
   variables:
-    PYVER: 3.12
+    PYVER: "3.12"
   stage: test
   tags: [cached-dind]
   image: python:3.12
@@ -179,7 +179,7 @@ unittest_py3.12:
 
 unittest_py3.13:
   variables:
-    PYVER: 3.13
+    PYVER: "3.13"
   tags: [cached-dind]
   stage: test
   image: python:3.13