diff --git a/pkgs/development/python-modules/xarray/default.nix b/pkgs/development/python-modules/xarray/default.nix
index 37488c13856c..5b501200dc82 100644
--- a/pkgs/development/python-modules/xarray/default.nix
+++ b/pkgs/development/python-modules/xarray/default.nix
@@ -93,7 +93,7 @@ buildPythonPackage rec {
       # nc-time-axis
       seaborn
     ];
-    complete = with self; accel ++ io ++ etc ++ parallel + viz;
+    complete = with self; accel ++ io ++ etc ++ parallel ++ viz;
   });
 
   nativeCheckInputs = [