diff --git a/.test-conda-env-py3.yml b/.test-conda-env-py3.yml
index d4340fc7454753ee93dca773b3258c30faf06eb3..89170283a82cd7d62dd2a57f60f60c96fc1cd4fb 100644
--- a/.test-conda-env-py3.yml
+++ b/.test-conda-env-py3.yml
@@ -5,7 +5,11 @@ channels:
 dependencies:
 - git
 - conda-forge::numpy
+
+# to avoid conflict with system openmpi's libhwloc
+- libhwloc=1
 - pocl
+
 - islpy
 - pyopencl
 - python=3