diff --git a/requirements_dev_optional.txt b/requirements_dev_optional.txt
index 1a6efc470f..8ae6ee354c 100644
--- a/requirements_dev_optional.txt
+++ b/requirements_dev_optional.txt
@@ -8,7 +8,7 @@ ipytree==0.2.1
 # version to get compatibility with azure storage emulator on appveyor (FIXME)
 azure-storage-blob==2.0.1 # pyup: ignore
 redis==3.5.3
-pymongo==3.11.4
+pymongo==4.15.3
 # optional test requirements
 tox==3.14.0
 coverage