diff --git a/scripts/pyivastest/IvasModeAnalyzer.py b/scripts/pyivastest/IvasModeAnalyzer.py
index 94e2646684d244e9eb75fa6a094537fea65e3e50..7e6d40b2e588a1cf33d0a2f0eb1ce71eeb78b3e4 100644
--- a/scripts/pyivastest/IvasModeAnalyzer.py
+++ b/scripts/pyivastest/IvasModeAnalyzer.py
@@ -187,8 +187,9 @@ class IvasModeAnalyzer(IvasModeCollector):
         all_log_files = os.listdir(log_dir)
         for mode in self.flat_mode_list:
             for f in all_log_files:
+                search_string = re.escape("_{}".format(mode))
                 if (
-                    re.search("_{}".format(mode), f)
+                    re.search(search_string, f)
                     and os.path.splitext(f)[1] == LOG_FILE_EXT
                 ):
                     # this is a log file belonging to the ivas_format