diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6bcfd56..129646d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -24,7 +24,7 @@ jobs:
         include:
           - os: ubuntu-latest
             python-version: "3.10"
-            pymc-version: "5.0.0"
+            pymc-version: "5.10.0"  # Oldest pymc version
     steps:
       - uses: actions/checkout@v4