diff --git a/edml/controllers/test_controller.py b/edml/controllers/test_controller.py
index ba5e7c187a745d13f8dae9673d3518fc9015b9d2..a3f0ca972c4b98e44e0d05d228db5562239ceb57 100644
--- a/edml/controllers/test_controller.py
+++ b/edml/controllers/test_controller.py
@@ -43,7 +43,7 @@ class TestController(BaseController):
 
     def _get_model_with_highest_postfix_number(self, model_save_path):
         """Returns the highest postfix number in the given directory for the configured model_prefix."""
-        model_prefix = self.__model_prefix__()
+        model_prefix = f"{self.__model_prefix__()}_client_"  # assume server and client weights were saved appropriately
         highest_postfix_number = 0
         for file in os.listdir(model_save_path):
             if file.startswith(model_prefix):