diff --git a/pkgs/development/python-modules/pyecotrend-ista/default.nix b/pkgs/development/python-modules/pyecotrend-ista/default.nix
index c281eb080388..7f0f59e7ed0b 100644
--- a/pkgs/development/python-modules/pyecotrend-ista/default.nix
+++ b/pkgs/development/python-modules/pyecotrend-ista/default.nix
@@ -45,6 +45,10 @@ buildPythonPackage rec {
     syrupy
   ];
 
+  pytestFlags = [
+    "--snapshot-warn-unused"
+  ];
+
   pythonImportsCheck = [ "pyecotrend_ista" ];
 
   meta = {