diff --git a/bin/pt-upgrade b/bin/pt-upgrade
index 2bdcd659..1417bf81 100755
--- a/bin/pt-upgrade
+++ b/bin/pt-upgrade
@@ -5328,7 +5328,7 @@ sub exec_event {
       my $t1 = time - $t0;
       $results->{query_time} = sprintf('%.6f', $t1);
       $results->{sth}        = $sth;
-      $results->{warnings}   = $self->get_warnings(host => $host);
+      $results->{warnings}   = $self->get_warnings(dbh => $host->dbh);
    };
    if ( $EVAL_ERROR ) {
       PTDEBUG && _d($EVAL_ERROR);
@@ -5341,12 +5341,12 @@ sub exec_event {
 
 sub get_warnings {
    my ($self, %args) = @_;
-   my @required_args = qw(host);
+   my @required_args = qw(dbh);
    foreach my $arg ( @required_args ) {
       die "I need a $arg argument" unless $args{$arg};
    }
-   my $host = $args{host};
-   my $warnings = $host->dbh->selectall_hashref('SHOW WARNINGS', 'code');
+   my $dbh = $args{dbh};
+   my $warnings = $dbh->selectall_hashref('SHOW WARNINGS', 'code');
    return $warnings;
 }
 
diff --git a/lib/EventExecutor.pm b/lib/EventExecutor.pm
index 62dc62ca..8c263d01 100644
--- a/lib/EventExecutor.pm
+++ b/lib/EventExecutor.pm
@@ -82,7 +82,7 @@ sub exec_event {
       my $t1 = time - $t0;
       $results->{query_time} = sprintf('%.6f', $t1);
       $results->{sth}        = $sth;
-      $results->{warnings}   = $self->get_warnings(host => $host);
+      $results->{warnings}   = $self->get_warnings(dbh => $host->dbh);
    };
    if ( $EVAL_ERROR ) {
       PTDEBUG && _d($EVAL_ERROR);
@@ -95,12 +95,12 @@ sub exec_event {
 
 sub get_warnings {
    my ($self, %args) = @_;
-   my @required_args = qw(host);
+   my @required_args = qw(dbh);
    foreach my $arg ( @required_args ) {
       die "I need a $arg argument" unless $args{$arg};
    }
-   my $host = $args{host};
-   my $warnings = $host->dbh->selectall_hashref('SHOW WARNINGS', 'code');
+   my $dbh = $args{dbh};
+   my $warnings = $dbh->selectall_hashref('SHOW WARNINGS', 'code');
    return $warnings;
 }
 
diff --git a/t/pt-upgrade/diff_rows.t b/t/pt-upgrade/diff_rows.t
index afabf194..75e9608a 100644
--- a/t/pt-upgrade/diff_rows.t
+++ b/t/pt-upgrade/diff_rows.t
@@ -68,16 +68,16 @@ test_diff (
    query1 => "select user from mysql.user order by user ASC",
    query2 => "select user from mysql.user order by user DESC",
    expect => [
-      {
-         row_number => 1,
-         sth1_rows  => [qw(msandbox)],
-         sth2_rows  => [qw(root)],
-      },
-      {
-         row_number => 2,
-         sth1_rows  => [qw(root)],
-         sth2_rows  => [qw(msandbox)],
-      }
+      [
+         1,
+         [qw(msandbox)],
+         [qw(root)],
+      ],
+      [
+         2,
+         [qw(root)],
+         [qw(msandbox)],
+      ]
    ],
 );
 
diff --git a/t/pt-upgrade/diff_warnings.t b/t/pt-upgrade/diff_warnings.t
index 331ca8b1..90cc6586 100644
--- a/t/pt-upgrade/diff_warnings.t
+++ b/t/pt-upgrade/diff_warnings.t
@@ -39,8 +39,9 @@ sub clear_warnings {
 $dbh1->do("INSERT INTO test.t VALUES (2, '', 123456789)");
 $dbh2->do("INSERT INTO test.t VALUES (3, '', 123456789)");
 
-my $w1 = pt_upgrade::get_warnings(dbh => $dbh1);
-my $w2 = pt_upgrade::get_warnings(dbh => $dbh2);
+my $event_exec = EventExecutor->new();
+my $w1 = $event_exec->get_warnings(dbh => $dbh1);
+my $w2 = $event_exec->get_warnings(dbh => $dbh2);
 
 my $error_1264 = {
    code    => '1264',
@@ -65,8 +66,8 @@ is_deeply(
 ) or diag(Dumper($w2));
 
 my $diffs = pt_upgrade::diff_warnings(
-   host1_warnings => $w1,
-   host2_warnings => $w2,
+   warnings1 => $w1,
+   warnings2 => $w2,
 );
 
 is_deeply(
@@ -76,17 +77,18 @@ is_deeply(
 ) or diag(Dumper($diffs));
 
 $diffs = pt_upgrade::diff_warnings(
-   host1_warnings => {},
-   host2_warnings => $w2,
+   warnings1 => {},
+   warnings2 => $w2,
 );
 
 is_deeply(
    $diffs,
    [
-      {
-         host1 => undef,
-         host2 => $error_1264,
-      },
+      [
+         1264,
+         undef,
+         $error_1264,
+      ],
    ],
    "host1 doesn't have the warning"
 ) or diag(Dumper($diffs));
@@ -97,8 +99,8 @@ is_deeply(
 
 $diffs = pt_upgrade::diff_warnings(
    ignore_warnings => { 1264 => 1 },
-   host1_warnings  => $w1,
-   host2_warnings  => $w2,
+   warnings1       => $w1,
+   warnings2       => $w2,
 );
 
 is_deeply(