diff --git a/environment.yml b/environment.yml
index 6f3f81d8a4d77..71d7e47894f9d 100644
--- a/environment.yml
+++ b/environment.yml
@@ -3,7 +3,7 @@ channels:
   - conda-forge
 dependencies:
   # required
-  - numpy>=1.16.5
+  - numpy>=1.16.5, <1.20 # gh-39513
   - python=3
   - python-dateutil>=2.7.3
   - pytz
diff --git a/requirements-dev.txt b/requirements-dev.txt
index f0d65104ead8e..33a315884612d 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>=1.16.5
+numpy>=1.16.5, <1.20
 python-dateutil>=2.7.3
 pytz
 asv