diff --git a/example_workflows/nfdi/source/envs/processing.yaml b/example_workflows/nfdi/source/envs/processing.yaml
index d4c2d9b..367874a 100644
--- a/example_workflows/nfdi/source/envs/processing.yaml
+++ b/example_workflows/nfdi/source/envs/processing.yaml
@@ -2,3 +2,4 @@ channels:
   - conda-forge
 dependencies:
   - fenics=2019.1.0=py39hf3d152e_26
+  - sympy=1.13.3
\ No newline at end of file