diff --git a/bin/pt-table-checksum b/bin/pt-table-checksum
index 476d3f4c..0c3f7858 100755
--- a/bin/pt-table-checksum
+++ b/bin/pt-table-checksum
@@ -5886,6 +5886,30 @@ use sigtrap 'handler', \&sig_int, 'normal-signals';
 my $oktorun      = 1;
 my $print_header = 1;
 
+# The following two hashes are used in exec_nibble().
+# They're static, so they do not need to be reset in main().
+# See also https://bugs.launchpad.net/percona-toolkit/+bug/919499
+
+# Completely ignore these error codes.
+my %ignore_code = (
+   # Error: 1592 SQLSTATE: HY000  (ER_BINLOG_UNSAFE_STATEMENT)
+   # Message: Statement may not be safe to log in statement format. 
+   # Ignore this warning because we have purposely set statement-based
+   # replication.
+   1592 => 1,
+);
+
+# Warn once per-table for these error codes if the error message
+# matches the pattern.
+my %warn_code = (
+   # Error: 1265 SQLSTATE: 01000 (WARN_DATA_TRUNCATED)
+   # Message: Data truncated for column '%s' at row %ld
+   1265 => {
+      # any pattern
+      # use MySQL's message for this warning
+   },
+);
+
 sub main {
    # Reset global vars else tests will fail in strange ways.
    @ARGV         = @_;
@@ -6923,27 +6947,6 @@ sub ts {
    return $msg ? "$ts $msg" : $ts;
 }
 
-{
-# Completely ignore these error codes.
-my %ignore_code = (
-   # Error: 1592 SQLSTATE: HY000  (ER_BINLOG_UNSAFE_STATEMENT)
-   # Message: Statement may not be safe to log in statement format. 
-   # Ignore this warning because we have purposely set statement-based
-   # replication.
-   1592 => 1,
-);
-
-# Warn once per-table for these error codes if the error message
-# matches the pattern.
-my %warn_code = (
-   # Error: 1265 SQLSTATE: 01000 (WARN_DATA_TRUNCATED)
-   # Message: Data truncated for column '%s' at row %ld
-   1265 => {
-      # any pattern
-      # use MySQL's message for this warning
-   },
-);
-
 sub exec_nibble {
    my (%args) = @_;
    my @required_args = qw(Cxn tbl NibbleIterator Retry Quoter OptionParser);
@@ -7089,7 +7092,6 @@ sub exec_nibble {
       }
    );
 }
-}
 
 {
 my $line_fmt = "%14s %6s %6s %8s %7s %7s %7s %-s\n";
diff --git a/sandbox/servers/5.5/data.tar.gz b/sandbox/servers/5.5/data.tar.gz
index d8d9507c..d4152496 100644
Binary files a/sandbox/servers/5.5/data.tar.gz and b/sandbox/servers/5.5/data.tar.gz differ
diff --git a/t/pt-table-checksum/bugs.t b/t/pt-table-checksum/bugs.t
index c4a10401..a8082926 100644
--- a/t/pt-table-checksum/bugs.t
+++ b/t/pt-table-checksum/bugs.t
@@ -38,7 +38,7 @@ elsif ( !$slave_dbh ) {
    plan skip_all => 'Cannot connect to sandbox slave1';
 }
 else {
-   plan tests => 5;
+   plan tests => 7;
 }
 
 # The sandbox servers run with lock_wait_timeout=3 and it's not dynamic
@@ -114,6 +114,28 @@ is_deeply(
    "Bug 987393 (empty table): checksums"
 ) or print STDERR Dumper($rows);
 
+# #############################################################################
+# https://bugs.launchpad.net/percona-toolkit/+bug/919499
+# MySQL error 1592 with MySQL 5.5.18+ and Perl 5.8
+# #############################################################################
+$output = output(
+   sub {
+      print `$trunk/bin/pt-table-checksum $master_dsn -t sakila.country 2>&1`;
+   }
+);
+
+is(
+   PerconaTest::count_checksum_results($output, 'errors'),
+   0,
+   "Bug 987393 (Perl 5.8 scoping): no errors"
+);
+
+is(
+   PerconaTest::count_checksum_results($output, 'rows'),
+   109,
+   "Bug 987393 (Perl 5.8 scoping): checksummed table"
+);
+
 # #############################################################################
 # Done.
 # #############################################################################