diff --git a/test-requirements.txt b/test-requirements.txt
index c735de8d5c..99fec7c3be 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -7,11 +7,13 @@ pytest-random-order
 nbsphinx
 sphinx_rtd_theme
 mypy==1.5.1
+types-mock
 types-python-dateutil
 types-requests
 types-paramiko
 mpi4py
 
+
 # sqlalchemy is needed for typechecking, so it's here
 # as well as at runtime for optional monitoring execution
 # (where it's specified in setup.py)