diff --git a/environment.yml b/environment.yml
index 2c06c321fdbc4..903babc3a7b37 100644
--- a/environment.yml
+++ b/environment.yml
@@ -3,7 +3,7 @@ channels:
   - conda-forge
 dependencies:
   # required
-  - numpy>=1.17.3
+  - numpy<1.21
   - python=3.8
   - python-dateutil>=2.7.3
   - pytz
diff --git a/requirements-dev.txt b/requirements-dev.txt
index a0d4c8e02acf6..b0f15ec82285f 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,7 +1,7 @@
 # This file is auto-generated from environment.yml, do not modify.
 # See that file for comments about the need/usage of each dependency.
 
-numpy>=1.17.3
+numpy<1.21
 python-dateutil>=2.7.3
 pytz
 asv