diff -u b/core/modules/migrate/src/Entity/Migration.php b/core/modules/migrate/src/Entity/Migration.php
--- b/core/modules/migrate/src/Entity/Migration.php
+++ b/core/modules/migrate/src/Entity/Migration.php
@@ -373,18 +373,16 @@
    * {@inheritdoc}
    */
   public function setMigrationStatus($status) {
-    \Drupal::state()->set('migrate.' . $this->id() . '.status', $status);
+    $migrate_status_store = \Drupal::keyValue('migrate_status');
+    $migrate_status_store->set($this->id(), $status);
   }
 
   /**
    * {@inheritdoc}
    */
   public function getMigrationStatus() {
-    $status = \Drupal::state()->get('migrate.' . $this->id() . '.status');
-    if (is_null($status)) {
-      $status = MigrationInterface::STATUS_IDLE;
-    }
-    return $status;
+    $migrate_status_store = \Drupal::keyValue('migrate_status');
+    return $migrate_status_store->get($this->id(), static::STATUS_IDLE);
   }
 
   /**
diff -u b/core/modules/migrate/src/MigrateExecutable.php b/core/modules/migrate/src/MigrateExecutable.php
--- b/core/modules/migrate/src/MigrateExecutable.php
+++ b/core/modules/migrate/src/MigrateExecutable.php
@@ -238,9 +238,8 @@
    */
   public function import() {
     // Only begin the import operation if the migration is currently idle.
-    if ($this->migration->getMigrationStatus() != MigrationInterface::STATUS_IDLE) {
-      $this->message->display(
-        $this->t('Migration @id is busy with another operation', array(
+    if ($this->migration->getMigrationStatus() !== MigrationInterface::STATUS_IDLE) {
+      $this->message->display($this->t('Migration @id is busy with another operation', array(
           '@id' => $this->migration->id(),
         )), 'error');
       return MigrationInterface::RESULT_FAILED;
@@ -279,7 +278,7 @@
     while ($source->valid()) {
       // Primarily looking for STATUS_STOPPING here, but we should quit on any
       // unexpected status.
-      if ($this->migration->getMigrationStatus() != MigrationInterface::STATUS_IMPORTING) {
+      if ($this->migration->getMigrationStatus() !== MigrationInterface::STATUS_IMPORTING) {
         break;
       }
       $row = $source->current();
diff -u b/core/modules/migrate/tests/src/Unit/MigrateTestCase.php b/core/modules/migrate/tests/src/Unit/MigrateTestCase.php
--- b/core/modules/migrate/tests/src/Unit/MigrateTestCase.php
+++ b/core/modules/migrate/tests/src/Unit/MigrateTestCase.php
@@ -9,6 +9,7 @@
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\Core\Database\Driver\fake\FakeConnection;
+use Drupal\migrate\Entity\MigrationInterface;
 
 /**
  * Provides setup and helper methods for Migrate module tests.
@@ -20,7 +21,7 @@
   /**
    * @var \Drupal\migrate\Entity\MigrationInterface::STATUS_*
    */
-  protected $migrationStatus;
+  protected $migrationStatus = MigrationInterface::STATUS_IDLE;
 
   /**
    * Retrieve a mocked migration.