diff --git a/.github/workflows/unittest-flux.yml b/.github/workflows/unittest-flux.yml
index 14fca90c..ec298d9a 100644
--- a/.github/workflows/unittest-flux.yml
+++ b/.github/workflows/unittest-flux.yml
@@ -42,7 +42,7 @@ jobs:
       shell: bash -l {0}
       timeout-minutes: 5
       run: |
-        mamba install -y flux-core coverage
+        mamba install -y flux-core=0.58.0 coverage
         pip install versioneer[toml]==0.29
         pip install . --no-deps --no-build-isolation
         cd tests