diff --git a/bin/pt-query-digest b/bin/pt-query-digest
index 12ffeaaf..3f5ee9f4 100755
--- a/bin/pt-query-digest
+++ b/bin/pt-query-digest
@@ -2679,7 +2679,7 @@ sub any_unix_timestamp {
 
 sub make_checksum {
    my ( $val ) = @_;
-   my $checksum = uc substr(md5_hex($val), -32);
+   my $checksum = uc substr(md5_hex($val), -16);
    warn ($checksum, ' checksum for ', $val);
    PTDEBUG && _d($checksum, 'checksum for', $val);
    return $checksum;