diff --git a/tests/src/Core/InstallerTest.php b/tests/src/Core/InstallerTest.php
index 9256581b16..c951823148 100644
--- a/tests/src/Core/InstallerTest.php
+++ b/tests/src/Core/InstallerTest.php
@@ -276,6 +276,17 @@ class InstallerTest extends MockedTest
 			true,
 			$install->getChecks());
 
+		$this->mockFunctionL10TCalls();
+		$this->setFunctions(['gmp_strval' => false]);
+		$install = new Installer();
+		self::assertFalse($install->checkFunctions());
+		self::assertCheckExist(11,
+			'GNU Multiple Precision PHP module',
+			'Error: GNU Multiple Precision PHP module required but not installed.',
+		false,
+			true,
+			$install->getChecks());
+
 		$this->mockFunctionL10TCalls();
 		$this->setFunctions([
 			'curl_init' => true,