diff --git a/pkgs/development/python-modules/watchdog/default.nix b/pkgs/development/python-modules/watchdog/default.nix
index 441630fe6f66..e5d742bef28d 100644
--- a/pkgs/development/python-modules/watchdog/default.nix
+++ b/pkgs/development/python-modules/watchdog/default.nix
@@ -5,6 +5,7 @@
 , argh
 , pathtools
 , pyyaml
+, flaky
 , pytest-timeout
 , pytestCheckHook
 , CoreServices
@@ -28,6 +29,7 @@ buildPythonPackage rec {
   ];
 
   checkInputs = [
+    flaky
     pytest-timeout
     pytestCheckHook
   ];