diff --git a/secureboot/esl-parser.py b/secureboot/esl-parser.py
index df5badf..bf21300 100644
--- a/secureboot/esl-parser.py
+++ b/secureboot/esl-parser.py
@@ -37,7 +37,7 @@ def main():
     hash_counter = 0
 
     if args.debug:
-        print("Input file size is {input_length}")
+        print(f"Input file size is {input_length}")
 
     #there may be multiple ESL structures concatenated together in the input file
     while head_index < input_length: