diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9bd4052..509d367 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -103,6 +103,7 @@ jobs:
                   environment-name: pypoman_test_env
                   create-args: >-
                       python=${{ matrix.python-version }}
+                      cddlib
                       cvxopt>=1.2.6
                       matplotlib>=3.3.4
                       numpy>=1.15.4