diff --git a/climax/main/download_ERA5.py b/climax/main/download_ERA5.py
index f308c6e891e81570d6fd0a80937440f424bc5b88..d19de35a35495e07a598c2915ce89e6e5be1326d 100644
--- a/climax/main/download_ERA5.py
+++ b/climax/main/download_ERA5.py
@@ -56,11 +56,11 @@ if __name__ == '__main__':
 
     # download data for the different variables
     for var in variables:
-        c.retrieve(product, CONFIG.update({'variable': var}), str(
+        c.retrieve(product, {**CONFIG, **{'variable': var}}, str(
             target.joinpath('_'.join(['ERA5', var, years[0], years[-1]])
                             + '.nc')))
 
     # Parallel(n_jobs=min(len(variables), os.cpu_count()), verbose=51)(
-    #     delayed(c.retrieve)(product, CONFIG.update({'variable': var}), str(
+    #     delayed(c.retrieve)(product, {**CONFIG, **{'variable': var}}, str(
     #         target.joinpath('_'.join(['ERA5', var, years[0], years[-1]])
     #                         + '.nc'))) for var in variables)