diff --git a/tests/_files/bar.txt b/tests/_files/bar.txt
new file mode 100644
index 00000000000..5acdde49d10
--- /dev/null
+++ b/tests/_files/bar.txt
@@ -0,0 +1 @@
+Test for compare file
diff --git a/tests/_files/foo.txt b/tests/_files/foo.txt
new file mode 100644
index 00000000000..0fdeb064721
--- /dev/null
+++ b/tests/_files/foo.txt
@@ -0,0 +1 @@
+Test file for compare
diff --git a/tests/unit/Framework/AssertTest.php b/tests/unit/Framework/AssertTest.php
index e44984edbd4..81fd17f31c9 100644
--- a/tests/unit/Framework/AssertTest.php
+++ b/tests/unit/Framework/AssertTest.php
@@ -1570,6 +1570,17 @@ public function testAssertStringNotMatchesFormatFile(): void
         $this->assertStringNotMatchesFormatFile(TEST_FILES_PATH . 'expectedFileFormat.txt', "FOO\n");
     }
 
+    public function testAssertFileEqualsCanonicalizing(): void
+    {
+        $this->assertFileEqualsCanonicalizing(TEST_FILES_PATH . 'foo.txt', TEST_FILES_PATH . 'foo.txt');
+
+        $this->assertFileEqualsCanonicalizing(TEST_FILES_PATH . 'foo.txt', TEST_FILES_PATH . 'bar.txt');
+
+        $this->expectException(AssertionFailedError::class);
+
+        $this->assertFileEqualsCanonicalizing(TEST_FILES_PATH . 'foo.txt', TEST_FILES_PATH . 'foo.xml');
+    }
+
     public function testStringsCanBeComparedForEqualityIgnoringCase(): void
     {
         $this->assertEqualsIgnoringCase('a', 'A');