diff --git a/src/Header/HeaderLine.php b/src/Header/HeaderLine.php
index e261485..baff0ea 100644
--- a/src/Header/HeaderLine.php
+++ b/src/Header/HeaderLine.php
@@ -36,12 +36,7 @@ public function __toString(): string
         $headerName = (string)$this->header->getName();
         $headerValue = (string)$this->header->getValue();
 
-        $firstFoldingAt = \strpos($headerValue, "\r\n");
-        if ($firstFoldingAt === false) {
-            $firstFoldingAt = \strlen($headerValue);
-        }
-
-        if (\strlen($headerName) + $firstFoldingAt > 76) {
+        if (\strlen($headerName) > 60) {
             return \sprintf("%s:\r\n %s", $headerName, $headerValue);
         }
 
diff --git a/src/Stream/OptimalTransferEncodedPhraseStream.php b/src/Stream/OptimalTransferEncodedPhraseStream.php
index 1ac38a3..655fac0 100644
--- a/src/Stream/OptimalTransferEncodedPhraseStream.php
+++ b/src/Stream/OptimalTransferEncodedPhraseStream.php
@@ -48,17 +48,19 @@ public function __construct(string $text, int $lineLength = 78, string $lineBrea
      */
     private function calculateOptimalStream(string $text): StreamInterface
     {
-        if (\strcspn($text, self::NON_7BIT_CHARS) === \strlen($text)) {
+        $length = \strlen($text);
+
+        if (\strcspn($text, self::NON_7BIT_CHARS) === $length) {
             $this->encoding = '7bit';
             return new AsciiEncodedStream($text, $this->lineLength, $this->lineBreak);
         }
 
-        if (\strcspn($text, HeaderValueParameter::RFC_822_T_SPECIAL) !== \strlen($text)) {
+        if (\strcspn($text, HeaderValueParameter::RFC_822_T_SPECIAL) !== $length) {
             $this->encoding = 'base64';
             return Base64EncodedStream::fromString($text, $this->lineLength, $this->lineBreak);
         }
 
-        if (\preg_match_all('/[\000-\010\013\014\016-\037\177-\377]/', $text) > (\strlen($text) / 3)) {
+        if (\preg_match_all('/[\000-\010\013\014\016-\037\177-\377]/', $text) > ($length / 3)) {
             $this->encoding = 'base64';
             return Base64EncodedStream::fromString($text, $this->lineLength, $this->lineBreak);
         }
diff --git a/src/Stream/OptimalTransferEncodedTextStream.php b/src/Stream/OptimalTransferEncodedTextStream.php
index 9c5a63e..1edb693 100644
--- a/src/Stream/OptimalTransferEncodedTextStream.php
+++ b/src/Stream/OptimalTransferEncodedTextStream.php
@@ -47,12 +47,14 @@ public function __construct(string $text, int $lineLength = 78, string $lineBrea
      */
     private function calculateOptimalStream(string $text): StreamInterface
     {
-        if (\strcspn($text, self::NON_7BIT_CHARS) === \strlen($text)) {
+        $length = \strlen($text);
+
+        if (\strcspn($text, self::NON_7BIT_CHARS) === $length) {
             $this->encoding = '7bit';
             return new AsciiEncodedStream($text, $this->lineLength, $this->lineBreak);
         }
 
-        if (\preg_match_all('/[\000-\010\013\014\016-\037\177-\377]/', $text) > (\strlen($text) / 3)) {
+        if (\preg_match_all('/[\000-\010\013\014\016-\037\177-\377]/', $text) > ($length / 3)) {
             $this->encoding = 'base64';
             return Base64EncodedStream::fromString($text, $this->lineLength, $this->lineBreak);
         }
diff --git a/test/Stub/MessageBodyCollection/attachment-long-filename.eml b/test/Stub/MessageBodyCollection/attachment-long-filename.eml
index 8553ac6..48e73f4 100644
--- a/test/Stub/MessageBodyCollection/attachment-long-filename.eml
+++ b/test/Stub/MessageBodyCollection/attachment-long-filename.eml
@@ -11,8 +11,7 @@ Content-Transfer-Encoding: 7bit
 --GenkgoMailV2Partfd6a87d339fb
 Content-Type: text/txt; charset=UTF-8
 Content-Transfer-Encoding: base64
-Content-Disposition:
- attachment; filename="AAAAAAAA-AAAAAAAAAAAA-AAA_AAAA AAAAAAA AAAAA AAAAA AAAAAAAAAAAA
+Content-Disposition: attachment; filename="AAAAAAAA-AAAAAAAAAAAA-AAA_AAAA AAAAAAA AAAAA AAAAA AAAAAAAAAAAA
  AAAAAAAAAAAAAAAAAA.pdf"
 
 dGVzdA==