diff --git a/setup.cfg b/setup.cfg
index 2ff9d91df..addee9138 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -29,11 +29,11 @@ classifiers =
 [options]
 packages = find:
 include_package_data = True
-python_requires = >=3.6
+python_requires = >=3.6,<3.9
 install_requires =
     pyglet>=1.5.8,<2
     pillow ~= 8.0
-    numpy ~= 1.19
+    numpy == 1.19.2
     pymunk ~= 5.7
     pyyaml ~= 5.3
     shapely ~= 1.7