diff --git a/phpunit/code/declare-strict-types-zero.php b/phpunit/code/declare-strict-types-zero.php
new file mode 100644
index 00000000..e3747999
--- /dev/null
+++ b/phpunit/code/declare-strict-types-zero.php
@@ -0,0 +1,2 @@
+<?php
+declare(strict_types=0);
diff --git a/phpunit/src/AssignTest.php b/phpunit/src/AssignTest.php
index e98f5012..a16ba693 100644
--- a/phpunit/src/AssignTest.php
+++ b/phpunit/src/AssignTest.php
@@ -124,4 +124,9 @@ class AssignTest extends \BaseTest
     {
         $this->exec("Cannot re-assign `\$x` from `php::Str` to `php::Array`", 're-assign-str-to-array.php');
     }
+
+    public function testStrictTypesZeroNotAllowed()
+    {
+        $this->exec("declare(strict_types=0) is not allowed, only strict_types=1 is supported", 'declare-strict-types-zero.php');
+    }
 }