diff --git a/pyproject.toml b/pyproject.toml
index d63b685c..48350d1d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -35,6 +35,7 @@ dependencies = [
     "matplotlib",
     "dask",
     "colorama",
+    "joblib"
 ]
 keywords = ["hydrology", "groundwater", "modeling", "Modflow 6", "flopy"]
 classifiers = [