diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3551012b..25254cb1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -83,7 +83,7 @@ jobs:
         -   uses: actions/checkout@v6
         -   name: "Main Script"
             run: |
-                echo "- matplotlib" >> .test-conda-env-py3.yml
+                echo "- matplotlib-base" >> .test-conda-env-py3.yml
                 curl -L -O https://gitlab.tiker.net/inducer/ci-support/raw/main/ci-support.sh
 
                 . ci-support.sh