diff --git a/src/FinalNewLineNormalizer.php b/src/FinalNewLineNormalizer.php
index 70dc3bd8..65273c51 100644
--- a/src/FinalNewLineNormalizer.php
+++ b/src/FinalNewLineNormalizer.php
@@ -24,6 +24,6 @@ public function normalize(string $json): string
             ));
         }
 
-        return $json . PHP_EOL;
+        return \rtrim($json) . PHP_EOL;
     }
 }
diff --git a/test/Unit/FinalNewLineNormalizerTest.php b/test/Unit/FinalNewLineNormalizerTest.php
index f9307c77..f2568862 100644
--- a/test/Unit/FinalNewLineNormalizerTest.php
+++ b/test/Unit/FinalNewLineNormalizerTest.php
@@ -56,7 +56,9 @@ public function testNormalizeEnsuresSingleFinalNewLine(string $whitespace)
 }
 JSON;
 
-        $normalized = \rtrim($json . $whitespace) . PHP_EOL;
+        $json .= $whitespace;
+
+        $normalized = \rtrim($json) . PHP_EOL;
 
         $normalizer = new FinalNewLineNormalizer();