diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index d40478957fa966ae23a21d7159634a7c0403a216..eb7d72bd7d37fd04c0ec88f4a01bb2116a08b613 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,7 +1,7 @@
 Python 2.7 POCL:
     script:
     - export PY_EXE=python2.7
-    - export PYOPENCL_TEST=portable
+    - export PYOPENCL_TEST=portable:pthread
     - export EXTRA_INSTALL="pybind11 numpy mako"
     - curl -L -O -k https://gitlab.tiker.net/inducer/ci-support/raw/master/build-and-test-py-project.sh
     - ". ./build-and-test-py-project.sh"
@@ -67,7 +67,7 @@ Python 3 K40:
 Python 3 POCL:
     script:
     - export PY_EXE=python3
-    - export PYOPENCL_TEST=portable
+    - export PYOPENCL_TEST=portable:pthread
     - export EXTRA_INSTALL="pybind11 numpy mako matplotlib"
     - curl -L -O -k https://gitlab.tiker.net/inducer/ci-support/raw/master/build-and-test-py-project.sh
     - ". ./build-and-test-py-project.sh"
@@ -84,7 +84,7 @@ Python 3 POCL Examples:
   script:
   - test -n "$SKIP_EXAMPLES" && exit
   - export PY_EXE=python3
-  - export PYOPENCL_TEST=portable
+  - export PYOPENCL_TEST=portable:pthread
   - export EXTRA_INSTALL="pybind11 numpy mako pyvisfile matplotlib"
   - curl -L -O -k https://gitlab.tiker.net/inducer/ci-support/raw/master/build-py-project-and-run-examples.sh
   - ". ./build-py-project-and-run-examples.sh"