diff --git a/tests/framework/i18n/FormatterNumberTest.php b/tests/framework/i18n/FormatterNumberTest.php
index e07a392..204ec51 100644
--- a/tests/framework/i18n/FormatterNumberTest.php
+++ b/tests/framework/i18n/FormatterNumberTest.php
@@ -374,6 +374,12 @@ class FormatterNumberTest extends TestCase
         $this->assertSame("1 KB", $this->formatter->asShortSize(1000));
         $this->assertSame("1.02 KB", $this->formatter->asShortSize(1023));
         $this->assertNotEquals("3 PB", $this->formatter->asShortSize(3 * 1000 * 1000 * 1000 * 1000 * 1000 * 1000)); // this is 3 EB not 3 PB
+        // string values
+        $this->assertSame("28.41 GB", $this->formatter->asShortSize(28406984038));
+        $this->assertSame("28.41 GB", $this->formatter->asShortSize((string)28406984038));
+        $this->assertSame("56.81 GB", $this->formatter->asShortSize(28406984038 + 28406984038));
+        $this->assertSame("56.81 GB", $this->formatter->asShortSize((string)(28406984038 + 28406984038)));
+
         // tests for base 1024
         $this->formatter->sizeFormatBase = 1024;
         $this->assertSame("1 KiB", $this->formatter->asShortSize(1024));