diff --git a/requirements.txt b/requirements.txt
index b80b169..ebd9d02 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,7 +2,7 @@ geographiclib
 geojson
 h5netcdf
 jsonschema
-numpy>=1.14
+numpy>=1.14,<2
 pandas
 pyparsing
 ruamel.yaml