diff --git a/admin/tool/mobile/tests/externallib_test.php b/admin/tool/mobile/tests/externallib_test.php
index 166fe5dee0447..5a17c579208c6 100644
--- a/admin/tool/mobile/tests/externallib_test.php
+++ b/admin/tool/mobile/tests/externallib_test.php
@@ -50,7 +50,8 @@ public function test_get_plugins_supporting_mobile() {
         $result = external::get_plugins_supporting_mobile();
         $result = external_api::clean_returnvalue(external::get_plugins_supporting_mobile_returns(), $result);
         $this->assertCount(0, $result['warnings']);
-        $this->assertCount(0, $result['plugins']);
+        $this->assertArrayHasKey('plugins', $result);
+        $this->assertTrue(is_array($result['plugins']));
     }
 
 }