diff --git a/t/pt-table-checksum/basics.t b/t/pt-table-checksum/basics.t
index e9b64000..eb947bbe 100644
--- a/t/pt-table-checksum/basics.t
+++ b/t/pt-table-checksum/basics.t
@@ -31,7 +31,7 @@ elsif ( !@{$master_dbh->selectall_arrayref('show databases like "sakila"')} ) {
    plan skip_all => 'sakila database is not loaded';
 }
 else {
-   plan tests => 5;
+   plan tests => 7;
 }
 
 # The sandbox servers run with lock_wait_timeout=3 and it's not dynamic
@@ -41,6 +41,7 @@ my @args       = ($master_dsn, qw(--lock-wait-timeout 3));
 
 my $row;
 my $output;
+my $exit_status;
 my $sample  = "t/pt-table-checksum/samples/";
 my $outfile = '/tmp/pt-table-checksum-results';
 my $repl_db = 'percona';
@@ -109,6 +110,35 @@ is(
    '78 checksums on slave'
 );
 
+# ############################################################################
+# --[no]replicate-check and, implicitly, the tool's exit status.
+# ############################################################################
+
+# Make one row on the slave differ.
+$row = $slave_dbh->selectrow_arrayref("select city, last_update from sakila.city where city_id=1");
+$slave_dbh->do("update sakila.city set city='test' where city_id=1");
+
+$exit_status = pt_table_checksum::main(@args,
+   qw(--quiet --quiet -t sakila.city));
+
+is(
+   $exit_status,
+   1,
+   "--replicate-check on by default, detects diff"
+);
+
+$exit_status = pt_table_checksum::main(@args,
+   qw(--quiet --quiet -t sakila.city --no-replicate-check));
+
+is(
+   $exit_status,
+   0,
+   "--no-replicate-check, no diff detected"
+);
+
+# Restore the row on the slave, else other tests will fail.
+$slave_dbh->do("update sakila.city set city='$row->[0]', last_update='$row->[1]' where city_id=1");
+
 # #############################################################################
 # Done.
 # #############################################################################
diff --git a/t/pt-table-checksum/fnv_64.t b/t/pt-table-checksum/fnv_64.t
index 84702f2f..274e8082 100644
--- a/t/pt-table-checksum/fnv_64.t
+++ b/t/pt-table-checksum/fnv_64.t
@@ -23,6 +23,9 @@ if ( !$master_dbh ) {
    plan skip_all => 'Cannot connect to sandbox master';
 }
 
+# TODO Need to update this test file. I don't have MySQL dev on my box
+# to compile the udf.
+
 my $output;
 my $cnf='/tmp/12345/my.sandbox.cnf';
 my $cmd = "$trunk/bin/pt-table-checksum -F $cnf -d test -t checksum_test 127.0.0.1";
@@ -33,7 +36,7 @@ eval { $master_dbh->do('DROP FUNCTION test.fnv_64'); };
 eval { $master_dbh->do("CREATE FUNCTION fnv_64 RETURNS INTEGER SONAME 'fnv_udf.so';"); };
 if ( $EVAL_ERROR ) {
    chomp $EVAL_ERROR;
-   plan skip_all => "Failed to created FNV_64 UDF: $EVAL_ERROR";
+   plan skip_all => "No FNV_64 UDF lib"
 }
 else {
    plan tests => 5;
diff --git a/t/pt-table-checksum/ignore_columns.t b/t/pt-table-checksum/ignore_columns.t
index 78b8f7ce..a54c2586 100644
--- a/t/pt-table-checksum/ignore_columns.t
+++ b/t/pt-table-checksum/ignore_columns.t
@@ -27,37 +27,66 @@ elsif ( !$slave_dbh ) {
    plan skip_all => 'Cannot connect to sandbox slave';
 }
 else {
-   plan tests => 2;
+   plan tests => 3;
 }
 
+# The sandbox servers run with lock_wait_timeout=3 and it's not dynamic
+# so we need to specify --lock-wait-timeout=3 else the tool will die.
+my $master_dsn = 'h=127.1,P=12345,u=msandbox,p=msandbox';
+my @args       = ($master_dsn, qw(--lock-wait-timeout 3)); 
 my $output;
-my $cnf='/tmp/12345/my.sandbox.cnf';
-my $cmd = "$trunk/bin/pt-table-checksum -F $cnf 127.0.0.1";
 
 $sb->create_dbs($master_dbh, [qw(test)]);
 $sb->load_file('master', 't/pt-table-checksum/samples/issue_94.sql');
 
-# #############################################################################
-# Issue 94: Enhance mk-table-checksum, add a --ignore-columns option
-# #############################################################################
+PerconaTest::wait_for_table($slave_dbh, 'test.issue_94', 'a=11');
+$slave_dbh->do("update test.issue_94 set c=''");
 
-$output = `$cmd -d test -t issue_94  P=12346 --algorithm ACCUM | awk '{print \$7}'`;
-like(
+sub get_diffs {
+   my ($output) = @_;
+   my (@diffs) = $output =~ m/
+      ^\S+\s+  # TS
+      \d+\s+   # ERRORS
+      (\d+)    # DIFFS
+   /gmx;
+   my $total_diffs = 0;
+   map { $total_diffs += $_ } @diffs;
+   return $total_diffs;
+}
+
+$output = output(
+   sub { pt_table_checksum::main(@args, qw(-d test -t issue_94)) },
+   trf => \&get_diffs,
+);
+is(
    $output,
-   qr/CHECKSUM\n00000006B6BDB8E6\n00000006B6BDB8E6/,
-   'Checksum ok with all 3 columns (issue 94 1/2)'
+   "1",
+   "Diff when column not ignored"
 );
 
-$output = `$cmd -d test -t issue_94 P=12346 --algorithm ACCUM --ignore-columns c | awk '{print \$7}'`;
-like(
+$output = output(
+   sub { pt_table_checksum::main(@args, qw(-d test -t issue_94),
+      qw(--ignore-columns c)) },
+   trf => \&get_diffs,
+);
+is(
    $output,
-   qr/CHECKSUM\n000000066094F8AA\n000000066094F8AA/,
-   'Checksum ok with ignored column (issue 94 2/2)'
+   "0",
+   "No diff when column ignored"
+);
+
+$output = output(
+   sub { pt_table_checksum::main(@args, qw(-d test -t issue_94),
+      qw(--ignore-columns c --explain)) },
+);
+unlike(
+   $output,
+   qr/`c`/,
+   "Ignored column is not in checksum query"
 );
 
 # #############################################################################
 # Done.
 # #############################################################################
 $sb->wipe_clean($master_dbh);
-$sb->wipe_clean($slave_dbh);
 exit;
diff --git a/t/pt-table-checksum/issue_1020.t b/t/pt-table-checksum/issue_1020.t
deleted file mode 100644
index 7c88da7b..00000000
--- a/t/pt-table-checksum/issue_1020.t
+++ /dev/null
@@ -1,53 +0,0 @@
-#!/usr/bin/env perl
-
-BEGIN {
-   die "The PERCONA_TOOLKIT_BRANCH environment variable is not set.\n"
-      unless $ENV{PERCONA_TOOLKIT_BRANCH} && -d $ENV{PERCONA_TOOLKIT_BRANCH};
-   unshift @INC, "$ENV{PERCONA_TOOLKIT_BRANCH}/lib";
-};
-
-use strict;
-use warnings FATAL => 'all';
-use English qw(-no_match_vars);
-use Test::More;
-
-use PerconaTest;
-use Sandbox;
-require "$trunk/bin/pt-table-checksum";
-
-my $dp  = new DSNParser(opts=>$dsn_opts);
-my $sb  = new Sandbox(basedir => '/tmp', DSNParser => $dp);
-my $dbh = $sb->get_dbh_for('master');
-
-if ( !$dbh ) {
-   plan skip_all => 'Cannot connect to sandbox master';
-}
-else {
-   plan tests => 1;
-}
-
-my $output;
-my $cnf = '/tmp/12345/my.sandbox.cnf';
-$sb->create_dbs($dbh, [qw(test)]);
-$sb->load_file('master', 't/pt-table-checksum/samples/checksum_tbl.sql');
-
-# #############################################################################
-# Issue 1020: mk-table-checksum should not checksum with --replicate-check=0
-# #############################################################################
-
-$output = output(
-   sub { pt_table_checksum::main("F=$cnf", qw(--replicate=test.checksum --replicate-check=0)) },
-   stderr => 1,
-);
-
-is (
-   $output,
-   '',
-   "mk-table-checksum should not checksum with --replicate-check=0 (issue 1020)"
-);
-
-# #############################################################################
-# Done.
-# #############################################################################
-$sb->wipe_clean($dbh);
-exit;