diff --git a/.github/workflows/conda/conda-env.yml b/.github/workflows/conda/conda-env.yml
index 49028c25d8..6d0dc37225 100644
--- a/.github/workflows/conda/conda-env.yml
+++ b/.github/workflows/conda/conda-env.yml
@@ -3,7 +3,7 @@ channels:
   - conda-forge
   - nodefaults
 dependencies:
-  - eigen
+  - eigen=3.4.0
   - hpp-fcl
   - numpy
   - boost