diff --git a/bin/pt-online-schema-change b/bin/pt-online-schema-change
index c78e813b..becc7a9f 100755
--- a/bin/pt-online-schema-change
+++ b/bin/pt-online-schema-change
@@ -6296,7 +6296,7 @@ sub check_orig_table {
    # Find a pk or unique index to use for the delete trigger.  can_nibble()
    # above returns an index, but NibbleIterator will use non-unique indexes,
    # so we have to do this again here.
-   my $indexes = $orig_tbl->{tbl_struct}->{indexes}; # brevity
+   my $indexes = $orig_tbl->{tbl_struct}->{keys}; # brevity
    foreach my $index ( $tp->sort_indexes($orig_tbl->{tbl_struct}) ) {
       if ( $index eq 'PRIMARY' || $indexes->{$index}->{is_unique} ) {
          PTDEBUG && _d('Delete trigger index:', Dumper($index));
diff --git a/t/pt-online-schema-change/bugs.t b/t/pt-online-schema-change/bugs.t
index ee6c9191..c483b90b 100644
--- a/t/pt-online-schema-change/bugs.t
+++ b/t/pt-online-schema-change/bugs.t
@@ -29,7 +29,7 @@ elsif ( !$slave_dbh ) {
    plan skip_all => 'Cannot connect to sandbox slave1';
 }
 else {
-   plan tests => 2;
+   plan tests => 3;
 }
 
 # The sandbox servers run with lock_wait_timeout=3 and it's not dynamic
@@ -66,6 +66,23 @@ unlike(
    "Bug 994002: doesn't choose non-PK"
 );
 
+# ############################################################################
+# https://bugs.launchpad.net/percona-toolkit/+bug/1002448
+# ############################################################################
+$sb->load_file('master', "$sample/bug-1002448.sql");
+
+$output = output(
+    sub { pt_online_schema_change::main(@args,
+            "$master_dsn,D=test1002448,t=table_name",
+            "--alter", "add column (foo int)",
+            qw(--chunk-size 2 --dry-run --print)) },
+);
+
+
+unlike $output,
+    qr/\QThe original table `test1002448`.`table_name` does not have a PRIMARY KEY or a unique index which is required for the DELETE trigger/,
+    "Bug 1002448: mistakenly uses indexes instead of keys";
+
 # #############################################################################
 # Done.
 # #############################################################################
diff --git a/t/pt-online-schema-change/samples/bug-1002448.sql b/t/pt-online-schema-change/samples/bug-1002448.sql
new file mode 100644
index 00000000..f7f012c5
--- /dev/null
+++ b/t/pt-online-schema-change/samples/bug-1002448.sql
@@ -0,0 +1,14 @@
+drop database if exists test1002448;
+create database test1002448;
+use test1002448;
+
+CREATE TABLE `table_name` (
+  `site` varchar(20) NOT NULL DEFAULT '',
+  `update_name` varchar(32) NOT NULL DEFAULT '',
+  `user` varchar(64) NOT NULL DEFAULT '',
+  `time` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
+  `value` varchar(64) NOT NULL DEFAULT '',
+  UNIQUE KEY `site` (`site`,`update_name`,`user`,`value`),
+  KEY `user` (`user`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+