diff --git a/unblob/handlers/archive/cpio.py b/unblob/handlers/archive/cpio.py
index 14128cb79f..43dc2836a4 100644
--- a/unblob/handlers/archive/cpio.py
+++ b/unblob/handlers/archive/cpio.py
@@ -368,8 +368,7 @@ def valid_checksum(self, header, start_offset: int) -> bool:
 
         for chunk in iterate_file(self.file, start_offset, file_size):
             calculated_checksum += sum(bytearray(chunk))
-
-        return header_checksum == calculated_checksum
+        return header_checksum == calculated_checksum & 0xFF_FF_FF_FF
 
 
 class _CPIOExtractorBase(Extractor):