diff --git a/cmake/Platform/size_script.py b/cmake/Platform/size_script.py
index 1ce3a37..b3342de 100644
--- a/cmake/Platform/size_script.py
+++ b/cmake/Platform/size_script.py
@@ -74,7 +74,7 @@ def eprint(*args, **kwargs):
 
 size_complete = 0
 if args.regex and args.regex != "":
-    nums = re.findall(args.regex + "", output, re.MULTILINE)
+    nums = re.findall(args.regex + "", output.decode(), re.MULTILINE)
     if nums:
         size_complete = sum(map(int, nums))
     else:
@@ -83,13 +83,13 @@ def eprint(*args, **kwargs):
 
 size_data = 0
 if args.regex_data and args.regex_data != "":
-    nums = re.findall(args.regex_data + "", output, re.MULTILINE)
+    nums = re.findall(args.regex_data + "", output.decode(), re.MULTILINE)
     if nums:
         size_data = sum(map(int, nums))
 
 size_eeprom = 0
 if args.regex_eeprom and args.regex_eeprom != "":
-    nums = re.findall(args.regex_eeprom + "", output, re.MULTILINE)
+    nums = re.findall(args.regex_eeprom + "", output.decode(), re.MULTILINE)
     if nums:
         size_eeprom = sum(map(int, nums))
 
@@ -150,4 +150,4 @@ def sizeof_fmt(num, suffix='B'):
 
 if size_eeprom > 0:
     eepromSizeStr = "EEPROM size: \t\t{} bytes".format(size_eeprom)
-    print(eepromSizeStr)
\ No newline at end of file
+    print(eepromSizeStr)