diff --git a/tests/SchemaTest.php b/tests/SchemaTest.php
index 93cfea967..5f5676f61 100644
--- a/tests/SchemaTest.php
+++ b/tests/SchemaTest.php
@@ -8,6 +8,7 @@
 use Throwable;
 use Yiisoft\Db\Command\CommandInterface;
 use Yiisoft\Db\Connection\ConnectionInterface;
+use Yiisoft\Db\Constraint\Constraint;
 use Yiisoft\Db\Driver\Pdo\PdoConnectionInterface;
 use Yiisoft\Db\Exception\Exception;
 use Yiisoft\Db\Exception\InvalidConfigException;
@@ -557,4 +558,18 @@ public function testDomainType(): void
 
         $db->close();
     }
+
+    public function testTableUniques(): void
+    {
+        $db = $this->getConnection(true);
+        $schema = $db->getSchema();
+
+        /** @var Constraint[] $tableUniques */
+        $tableUniques = $schema->getTableUniques('table_unique_index');
+
+        $this->assertCount(3, $tableUniques);
+        $this->assertSame(['one_unique'], $tableUniques[0]->getColumnNames());
+        $this->assertSame(['two_unique_1', 'two_unique_2'], $tableUniques[1]->getColumnNames());
+        $this->assertSame(['unique_index'], $tableUniques[2]->getColumnNames());
+    }
 }
diff --git a/tests/Support/Fixture/pgsql.sql b/tests/Support/Fixture/pgsql.sql
index 5b63cf727..c5dd8b85c 100644
--- a/tests/Support/Fixture/pgsql.sql
+++ b/tests/Support/Fixture/pgsql.sql
@@ -35,6 +35,7 @@ DROP TABLE IF EXISTS "T_upsert";
 DROP TABLE IF EXISTS "T_upsert_1";
 DROP TABLE IF EXISTS "table_with_array_col";
 DROP TABLE IF EXISTS "table_uuid";
+DROP TABLE IF EXISTS "table_unique_index";
 
 DROP SCHEMA IF EXISTS "schema1" CASCADE;
 DROP SCHEMA IF EXISTS "schema2" CASCADE;
@@ -454,3 +455,15 @@ CREATE TABLE "table_uuid" (
     "uuid" uuid NOT NULL PRIMARY KEY DEFAULT uuid_generate_v4(),
     "col" varchar(16)
 );
+
+CREATE TABLE "table_unique_index" (
+    "id" serial PRIMARY KEY,
+    "one_unique" integer UNIQUE,
+    "two_unique_1" integer,
+    "two_unique_2" integer,
+    "unique_index" integer,
+    "non-unique" integer,
+    UNIQUE ("two_unique_1", "two_unique_2")
+);
+
+CREATE UNIQUE INDEX ON "table_unique_index" ("unique_index") INCLUDE ("non-unique");