diff --git a/environment.yml b/environment.yml
index 5ecac1b8d..3511e74a6 100644
--- a/environment.yml
+++ b/environment.yml
@@ -20,6 +20,7 @@ dependencies: #! Keep in sync with [tool.pixi.dependencies] in pyproject.toml
   - uxarray>=2025.3.0
   - xgcm>=0.9.0
   - pooch
+  - cf_xarray
 
   # Notebooks
   - trajan
diff --git a/pyproject.toml b/pyproject.toml
index f8309e6da..c4fefdf09 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -34,6 +34,7 @@ dependencies = [
   "uxarray",
   "pooch",
   "xgcm >=0.9.0",
+  "cf_xarray",
 ]
 
 [project.urls]
@@ -106,6 +107,7 @@ pydata-sphinx-theme = "*"
 sphinx-autobuild = "*"
 myst-parser = "*"
 sphinxcontrib-mermaid = "*"
+cf_xarray = "*"
 
 [tool.pixi.pypi-dependencies]
 parcels = { path = ".", editable = true }