diff --git a/requirements-test.txt b/requirements-test.txt
index 243b9f6..424fc71 100644
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -1,6 +1,6 @@
 apache-libcloud
-azure-storage-blob >= 12.0
+azure-storage-blob >= 12.0, != 12.9.0  # version 12.9.0 breaks mypy https://github.com/Azure/azure-sdk-for-python/pull/20891
 pytest
 python-cephlibs
 types-pyyaml
 types-requests