diff --git a/example_workflows/nfdi/source/envs/preprocessing.yaml b/example_workflows/nfdi/source/envs/preprocessing.yaml
index d9a2660..ef8df53 100644
--- a/example_workflows/nfdi/source/envs/preprocessing.yaml
+++ b/example_workflows/nfdi/source/envs/preprocessing.yaml
@@ -3,3 +3,4 @@ channels:
 dependencies:
   - gmsh=4.6.0=hd134328_0
   - meshio=5.0.5=pyhd8ed1ab_0
+  - numpy<2