diff --git a/src/copyout.c b/src/copyout.c
index 72f1989..ee6f24a 100644
--- a/src/copyout.c
+++ b/src/copyout.c
@@ -59,7 +59,7 @@ read_for_checksum (int in_file_des, int file_size, char *file_name)
   if (lseek (in_file_des, 0L, SEEK_SET))
     error (1, errno, _("cannot read checksum for %s"), file_name);
 
-  return crc;
+  return crc & CHKSUM_MAX;
 }
 
 /* Write out NULs to fill out the rest of the current block on
@@ -381,7 +381,7 @@ write_out_new_ascii_header (const char *magic_string,
 			 _("name size")))
     return 1;
   p += 8;
-  to_ascii (p, file_hdr->c_chksum & 0xffffffff, 8, LG_16);
+  to_ascii (p, file_hdr->c_chksum & CHKSUM_MAX, 8, LG_16);
 
   tape_buffered_write (ascii_header, out_des, sizeof ascii_header);
 
diff --git a/src/extern.h b/src/extern.h
index 4f94d40..b274690 100644
--- a/src/extern.h
+++ b/src/extern.h
@@ -205,6 +205,8 @@ int cpio_create_dir (struct cpio_file_stat *file_hdr, int existing_dir);
 #define LG_8  3
 #define LG_16 4
 
+#define CHKSUM_MAX 0xffffffffu
+
 uintmax_t from_ascii (char const *where, size_t digs, unsigned logbase);
 
 #define FROM_OCTAL(f) from_ascii (f, sizeof f, LG_8)
diff --git a/src/util.c b/src/util.c
index 00953d5..e307c58 100644
--- a/src/util.c
+++ b/src/util.c
@@ -413,6 +413,8 @@ tape_toss_input (int in_des, off_t num_bytes)
       input_size -= space_left;
       bytes_left -= space_left;
     }
+
+  crc &= CHKSUM_MAX;
 }
 
 void
@@ -461,6 +463,8 @@ copy_files_tape_to_disk (int in_des, int out_des, off_t num_bytes)
       input_size -= size;
       in_buff += size;
     }
+
+  crc &= CHKSUM_MAX;
 }
 /* Copy a file using the input and output buffers, which may start out
    partly full.  After the copy, the files are not closed nor the last
@@ -514,6 +518,8 @@ copy_files_disk_to_tape (int in_des, int out_des, off_t num_bytes,
       input_size -= size;
       in_buff += size;
     }
+
+  crc &= CHKSUM_MAX;
 }
 /* Copy a file using the input and output buffers, which may start out
    partly full.  After the copy, the files are not closed nor the last
@@ -564,6 +570,8 @@ copy_files_disk_to_disk (int in_des, int out_des, off_t num_bytes,
       input_size -= size;
       in_buff += size;
     }
+
+  crc &= CHKSUM_MAX;
 }
 
 /* Warn if file changed while it was being copied.  */