diff --git a/environment.yml b/environment.yml
index 5b9fe6a605a81500f32b6e1b92e9b59e47976c56..8eb7402decd5073ce1a68691c8479db362699f77 100644
--- a/environment.yml
+++ b/environment.yml
@@ -5,10 +5,8 @@ channels:
 - conda-forge
 
 dependencies:
-- netcdf4
-- numpy
+- python=3.7.4
 - cdo
 - nco
 - eccodes
-- six
-- iris>=2.2
+- iris>=2.4
diff --git a/setup.py b/setup.py
index f4571a319913c9d946200bd3bb8344714a42f65e..ce66c25dd6231cdd5c44aa5401c66089f4726523 100644
--- a/setup.py
+++ b/setup.py
@@ -24,7 +24,7 @@ REQUIREMENTS = {
         "cdo>=1.3.4",
         "cfgrib",
         "dask[array]",
-        "diagonals",
+        "diagonals>=0.2"
         "netCDF4",
         "nco>=0.0.3",
         "numba",