diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index a47f24092f..9030302d8a 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -10,6 +10,7 @@ Yii Framework 2 Change Log
 - Bug #9796: Initialization of not existing `yii\grid\ActionColumn` default buttons (arogachev)
 - Bug #12681: Changed `data` column type from `text` to `blob` to handle null-byte (`\0`) in serialized RBAC rule properly (silverfire)
 - Bug #12714: Fixed `yii\validation\EmailValidator` to prevent false-positives checks when property `checkDns` is set to `true` (silverfire)
+- Bug #12735: Fixed `yii\console\controllers\MigrateController` creating multiple primary keys for field `bigPrimaryKey:unsigned` (SG5)
 - Bug #12791: Fixed `yii\behaviors\AttributeTypecastBehavior` unable to automatically detect `attributeTypes`, triggering PHP Fatal Error (klimov-paul)
 - Bug #12803, #12921: Fixed BC break in `yii.activeForm.js` introduced in #11999. Reverted commit 3ba72da (silverfire)
 - Bug #12810: Fixed `yii\rbac\DbManager::getChildRoles()` and `yii\rbac\PhpManager::getChildRoles()` throws an exception when role has no child roles (mysterydragon)
diff --git a/framework/console/controllers/MigrateController.php b/framework/console/controllers/MigrateController.php
index a91c6220ef..2b9866afbf 100644
--- a/framework/console/controllers/MigrateController.php
+++ b/framework/console/controllers/MigrateController.php
@@ -462,7 +462,7 @@ class MigrateController extends BaseMigrateController
     protected function addDefaultPrimaryKey(&$fields)
     {
         foreach ($fields as $field) {
-            if ($field['decorators'] === 'primaryKey()' || $field['decorators'] === 'bigPrimaryKey()') {
+            if (false !== strripos($field['decorators'], 'primarykey()')) {
                 return;
             }
         }
diff --git a/tests/data/console/migrate_create/create_unsigned_big_pk.php b/tests/data/console/migrate_create/create_unsigned_big_pk.php
new file mode 100644
index 0000000000..54b357423d
--- /dev/null
+++ b/tests/data/console/migrate_create/create_unsigned_big_pk.php
@@ -0,0 +1,32 @@
+<?php
+
+return <<<CODE
+<?php
+
+use yii\db\Migration;
+
+/**
+ * Handles the creation of table `{table}`.
+ */
+class {$class} extends Migration
+{
+    /**
+     * @inheritdoc
+     */
+    public function up()
+    {
+        \$this->createTable('{table}', [
+            'brand_id' => \$this->bigPrimaryKey()->unsigned(),
+        ]);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function down()
+    {
+        \$this->dropTable('{table}');
+    }
+}
+
+CODE;
diff --git a/tests/data/console/migrate_create/create_unsigned_pk.php b/tests/data/console/migrate_create/create_unsigned_pk.php
new file mode 100644
index 0000000000..1c6984326b
--- /dev/null
+++ b/tests/data/console/migrate_create/create_unsigned_pk.php
@@ -0,0 +1,32 @@
+<?php
+
+return <<<CODE
+<?php
+
+use yii\db\Migration;
+
+/**
+ * Handles the creation of table `{table}`.
+ */
+class {$class} extends Migration
+{
+    /**
+     * @inheritdoc
+     */
+    public function up()
+    {
+        \$this->createTable('{table}', [
+            'brand_id' => \$this->primaryKey()->unsigned(),
+        ]);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function down()
+    {
+        \$this->dropTable('{table}');
+    }
+}
+
+CODE;
diff --git a/tests/framework/console/controllers/MigrateControllerTest.php b/tests/framework/console/controllers/MigrateControllerTest.php
index c22cd74733..c95d1cb253 100644
--- a/tests/framework/console/controllers/MigrateControllerTest.php
+++ b/tests/framework/console/controllers/MigrateControllerTest.php
@@ -95,6 +95,14 @@ class MigrateControllerTest extends TestCase
                 'fields' => 'title:primaryKey,body:text:notNull,price:money(11,2)',
             ]);
 
+            $this->assertCommandCreatedFile('create_unsigned_pk', $migrationName, $table, [
+                'fields' => 'brand_id:primaryKey:unsigned',
+            ]);
+
+            $this->assertCommandCreatedFile('create_unsigned_big_pk', $migrationName, $table, [
+                'fields' => 'brand_id:bigPrimaryKey:unsigned',
+            ]);
+
             $this->assertCommandCreatedFile('create_id_pk', $migrationName, $table, [
                 'fields' => 'id:primaryKey,
                     address:string,