diff --git a/pkgs/development/tools/backblaze-b2/default.nix b/pkgs/development/tools/backblaze-b2/default.nix
index 76301b5f4820..3ed49c05bec9 100644
--- a/pkgs/development/tools/backblaze-b2/default.nix
+++ b/pkgs/development/tools/backblaze-b2/default.nix
@@ -46,7 +46,9 @@ python3Packages.buildPythonApplication rec {
     backoff
     more-itertools
     pexpect
-    pytestCheckHook
+
+    # backblaze-b2 requires pytest 7 to complete tests.
+    (pytestCheckHook.override { pytest = pytest_7; })
   ];
 
   preCheck = ''