diff --git a/tar.py b/tar.py
index 48c8dcf..81b7226 100644
--- a/tar.py
+++ b/tar.py
@@ -61,7 +61,7 @@ def header_chunk(filename: str, filepath: str) -> bytes:
 
     # POSIX 1003.1-1990: 255 empty bytes
 
-    # Compute the checksum: we start at 248 which are the 8 fields of checksum filled with spaces (32 * 8)
+    # Compute the checksum: we start at 256 which are the 8 fields of checksum filled with spaces (32 * 8)
     checksum = oct(functools.reduce(lambda x, y: x + y, buffer, 256)).rjust(6, '0').encode('ascii')
     buffer[148:154] = checksum