diff --git a/setup.cfg b/setup.cfg
index 6fb9ffc79..75680fb54 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -45,6 +45,8 @@ install_requires =
     jsonschema
     keyring
     keyrings.alt
+    # Remove this line once hdmf supports h5py v3.0+:
+    numpy >=1.16, <1.19.4
     pycryptodomex  # for EncryptedKeyring backend in keyrings.alt
     pydantic >= 1.8.1
     pynwb >= 1.0.3,!=1.1.0