diff --git a/core/modules/system/tests/src/Kernel/System/SystemGetInfoTest.php b/core/modules/system/tests/src/Kernel/System/SystemGetInfoTest.php
index f0bb9e74c0..cd42fa4870 100644
--- a/core/modules/system/tests/src/Kernel/System/SystemGetInfoTest.php
+++ b/core/modules/system/tests/src/Kernel/System/SystemGetInfoTest.php
@@ -17,15 +17,28 @@ class SystemGetInfoTest extends KernelTestBase {
    * Tests system_get_info().
    */
   public function testSystemGetInfo() {
-    $this->assertEquals('System', system_get_info('module', 'system')['name']);
+    $system_module_info = system_get_info('module', 'system');
+    $this->assertSame('System', $system_module_info['name']);
+    $this->assertSame(['system' => $system_module_info], system_get_info('module'));
+
     // The User module is not installed so system_get_info() should return
     // an empty array.
-    $this->assertEquals([], system_get_info('module', 'user'));
+    $this->assertSame([], system_get_info('module', 'user'));
 
     // Install the User module and check system_get_info() returns the correct
     // information.
     $this->container->get('module_installer')->install(['user']);
-    $this->assertEquals('User', system_get_info('module', 'user')['name']);
+    $user_module_info = system_get_info('module', 'user');
+    $this->assertSame('User', $user_module_info['name']);
+    $this->assertSame(['system' => $system_module_info, 'user' => $user_module_info], system_get_info('module'));
+
+    // Test theme info. There are no themes installed yet.
+    $this->assertSame([], system_get_info('theme', 'stable'));
+    $this->assertSame([], system_get_info('theme'));
+    $this->container->get('theme_installer')->install(['stable']);
+    $stable_theme_info = system_get_info('theme', 'stable');
+    $this->assertSame('Stable', $stable_theme_info['name']);
+    $this->assertSame(['stable' => $stable_theme_info], system_get_info('theme'));
   }
 
 }