diff --git a/simple_ortho/__init__.py b/simple_ortho/__init__.py
index 9f9db73..35638ae 100644
--- a/simple_ortho/__init__.py
+++ b/simple_ortho/__init__.py
@@ -18,7 +18,7 @@
 import pathlib
 
 # enable on-demand download of proj transformation grids
-os.environ.update(PROJ_NETWORK='ON', PROJ_ONLY_BEST_DEFAULT='ON', ALLOW_ELLIPSOIDAL_HEIGHT_AS_VERTICAL_CRS='NO')
+os.environ.update(PROJ_NETWORK='ON', PROJ_ONLY_BEST_DEFAULT='ON')
 
 # path to package root
 if '__file__' in globals():