diff --git a/server/lib/python/cartodb_services/cartodb_services/mapzen/isolines.py b/server/lib/python/cartodb_services/cartodb_services/mapzen/isolines.py
index 9a75075..95294ad 100644
--- a/server/lib/python/cartodb_services/cartodb_services/mapzen/isolines.py
+++ b/server/lib/python/cartodb_services/cartodb_services/mapzen/isolines.py
@@ -7,7 +7,7 @@ class MapzenIsolines:
     MAX_ITERS = 5
     TOLERANCE = 0.1
 
-    EARTH_RADIUS_METERS = 6371000
+    EARTH_RADIUS_METERS = 6367444
 
     def __init__(self, matrix_client):
         self._matrix_client = matrix_client