diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 803e724..66edc8f 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -68,6 +68,7 @@ jobs:
           pip uninstall -y numpy
           conda install numpy==1.20.0
           pip install -r requirements/bayes_opt.txt
+          pip uninstall -y numpy
           conda install numpy==1.20.0
 
       - name: Check installations of packages.