diff --git a/tests/Composer/Test/Command/InstallCommandTest.php b/tests/Composer/Test/Command/InstallCommandTest.php
index 08a9153fd..8dc1c911e 100644
--- a/tests/Composer/Test/Command/InstallCommandTest.php
+++ b/tests/Composer/Test/Command/InstallCommandTest.php
@@ -155,9 +155,9 @@ class InstallCommandTest extends TestCase
         // Confirm that dependency installation failed and system communicated
         // this with its exit code and text output.
         $this->assertNotEquals(0, $tester->getStatusCode());
-        $this->assertStringContainsString(
-            'is not found for package test/two',
-            \str_replace(PHP_EOL, '', $tester->getDisplay())
+        $this->assertMatchesRegularExpression(
+            '/is[[:blank:]]+not[[:blank:]]+found[[:blank:]]+for[[:blank:]]+package[[:blank:]]+test\\/two/',
+            $tester->getDisplay()
         );
     }