diff --git a/src/utils/exceptions.py b/src/utils/exceptions.py
index 745472d2ed9cb002c394ed8631c4e9fa269d3502..52c886cb78c1c1db2b50891ec90e877753e5d95c 100644
--- a/src/utils/exceptions.py
+++ b/src/utils/exceptions.py
@@ -21,7 +21,7 @@ class ISOCheckError(Exception):
         self.message = message
  
     def __str__(self):
-        return f"ISOCheckError: {self.message}"
+        return "ISOCheckError: {}".format(self.message)
 
 class ReportGenerateError(Exception):
     """app report generate error
@@ -30,4 +30,4 @@ class ReportGenerateError(Exception):
         self.message = message
  
     def __str__(self):
-        return f"ReportGenerateError: {self.message}"
+        return "ReportGenerateError: {}".format(self.message)