diff --git a/pyproject.toml b/pyproject.toml
index fd4881ef5..2e6b180f8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -47,6 +47,7 @@ dependencies = [
     "cartopy >=0.18.0",
     "cmocean",
     "dask",
+    "f90nml",
     "gsw",
     "lxml",
     "matplotlib >=3.9.0",