diff --git a/.circleci/config.yml b/.circleci/config.yml
index e1ad0dd578..8e5f38b84f 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -159,7 +159,7 @@ jobs:
     working_directory: /esmvaltool
     docker:
       - image: condaforge/mambaforge
-    resource_class: small
+    resource_class: medium
     steps:
       - run:
           command: |