diff --git a/WordPress/Tests/Files/FileNameUnitTest.php b/WordPress/Tests/Files/FileNameUnitTest.php
index 905147956d..c56d3661f2 100644
--- a/WordPress/Tests/Files/FileNameUnitTest.php
+++ b/WordPress/Tests/Files/FileNameUnitTest.php
@@ -9,7 +9,11 @@
 
 namespace WordPressCS\WordPress\Tests\Files;
 
+use PHP_CodeSniffer\Files\DummyFile;
+use PHP_CodeSniffer\Ruleset;
 use PHP_CodeSniffer\Tests\Standards\AbstractSniffUnitTest;
+use PHPCSUtils\BackCompat\Helper;
+use PHPCSUtils\TestUtils\ConfigDouble;
 
 /**
  * Unit test class for the FileName sniff.
@@ -172,4 +176,26 @@ public function getErrorList( $testFile = '' ) {
 	public function getWarningList() {
 		return array();
 	}
+
+	/**
+	 * Test the sniff bails early when handling STDIN.
+	 *
+	 * @return void
+	 */
+	public function testStdIn() {
+		$config = new ConfigDouble();
+		Helper::setConfigData( 'installed_paths', dirname( dirname( __DIR__ ) ), true, $config );
+		$config->standards = array( 'WordPress' );
+		$config->sniffs    = array( 'WordPress.Files.FileName' );
+
+		$ruleset = new Ruleset( $config );
+
+		$content = '<?php ';
+		$file    = new DummyFile( $content, $ruleset, $config );
+		$file->process();
+
+		$this->assertSame( 0, $file->getErrorCount() );
+		$this->assertSame( 0, $file->getWarningCount() );
+		$this->assertCount( 0, $file->getErrors() );
+	}
 }
diff --git a/WordPress/Tests/Utils/I18nTextDomainFixerUnitTest.php b/WordPress/Tests/Utils/I18nTextDomainFixerUnitTest.php
index cac3a5983c..a8c7c95e84 100644
--- a/WordPress/Tests/Utils/I18nTextDomainFixerUnitTest.php
+++ b/WordPress/Tests/Utils/I18nTextDomainFixerUnitTest.php
@@ -9,8 +9,11 @@
 
 namespace WordPressCS\WordPress\Tests\Utils;
 
+use PHP_CodeSniffer\Files\DummyFile;
+use PHP_CodeSniffer\Ruleset;
 use PHP_CodeSniffer\Tests\Standards\AbstractSniffUnitTest;
 use PHPCSUtils\BackCompat\Helper;
+use PHPCSUtils\TestUtils\ConfigDouble;
 
 /**
  * Unit test class for the I18nTextDomainFixer sniff.
@@ -200,4 +203,32 @@ public function getWarningList( $testFile = '' ) {
 				return array();
 		}
 	}
+
+	/**
+	 * Test the sniff bails early when handling a plugin header passed via STDIN.
+	 *
+	 * @return void
+	 */
+	public function testStdIn() {
+		$config = new ConfigDouble();
+		Helper::setConfigData( 'installed_paths', dirname( dirname( __DIR__ ) ), true, $config );
+		$config->standards = array( 'WordPress' );
+		$config->sniffs    = array( 'WordPress.Utils.I18nTextDomainFixer' );
+
+		$ruleset = new Ruleset( $config );
+
+		$content = '<?php // phpcs:set WordPress.Utils.I18nTextDomainFixer new_text_domain test-std-in
+/**
+ * Plugin Name: Missing text domain, docblock format.
+ * Plugin URI: https://www.bigvoodoo.com/
+ * Description: Sniff triggers a missing text domain error for a normal file, but not for STDIN.
+ */';
+
+		$file = new DummyFile( $content, $ruleset, $config );
+		$file->process();
+
+		$this->assertSame( 0, $file->getErrorCount() );
+		$this->assertSame( 0, $file->getWarningCount() );
+		$this->assertCount( 0, $file->getErrors() );
+	}
 }