diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1a366b6f72..841b0c66d0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -316,6 +316,7 @@ jobs:
         curl -LO https://raw.githubusercontent.com/GiovanniBussi/conda-ci/master/conda-ci
         source ./conda-ci install
         source ./conda-ci install-conda-build
+        conda install "conda-build<4"
     - name: Build PLUMED
       run: |
         source activate base