diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 7497b28..c2f2c81 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -59,7 +59,7 @@ jobs:
       - name: Install SMAC (Linux and MacOS).
         if: runner.os != 'Windows'
         run: |
-          conda install swig scipy<=1.6
+          conda install swig "scipy<=1.6"
           pip install -r requirements/bayes_opt.txt
 
       - name: Install GPy and GPyOpt