diff --git a/requirements/embedded.txt b/requirements/embedded.txt
index 64f6d4e..729bc56 100644
--- a/requirements/embedded.txt
+++ b/requirements/embedded.txt
@@ -1,4 +1,4 @@
 pyvista>=0.4 #3D visualisation/vtk meshing
 LoopStructural>=1.6.6 #3D geological modelling
 geoh5py>=0.9 #saving models to hdf5
-dill>=0.3.9     #saving models to python
+dill>=0.4.1     #saving models to python
diff --git a/requirements/testing.txt b/requirements/testing.txt
index 1728f90..2da2edb 100644
--- a/requirements/testing.txt
+++ b/requirements/testing.txt
@@ -6,7 +6,7 @@ packaging>=23
 pyvista>=0.4 #3D visualisation/vtk meshing
 LoopStructural>=1.6.23 #3D geological modelling
 geoh5py>=0.9 #saving models to hdf5
-dill>=0.3.9     #saving models to python
+dill>=0.4.1     #saving models to python
 shapely
 geopandas
 map2loop~=3.3.1