diff --git a/requirements-dev.txt b/requirements-dev.txt
index 3f11ff0..c7154f9 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -3,5 +3,6 @@ xarray
 dask
 toolz
 netCDF4
+zarr
 pytest
 pytest-cov
diff --git a/requirements.txt b/requirements.txt
index 7ee8d7a..71094d1 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,3 +2,5 @@ numpy
 xarray
 dask
 toolz
+netCDF4
+zarr