diff --git a/src/Protocol/Imap.php b/src/Protocol/Imap.php
index d8b20724..ce9f87da 100644
--- a/src/Protocol/Imap.php
+++ b/src/Protocol/Imap.php
@@ -380,7 +380,7 @@ public function requestAndResponse($command, $tokens = [], $dontParse = false)
     /**
      * escape one or more literals i.e. for sendRequest
      *
-     * @param  string|array $string the literal/-s
+     * @param  string $string the literal/-s
      * @return string|array escape literals, literals with newline ar returned
      *                      as array('{size}', 'string');
      */
diff --git a/src/Transport/Envelope.php b/src/Transport/Envelope.php
index a1e9bc51..c63605dd 100644
--- a/src/Transport/Envelope.php
+++ b/src/Transport/Envelope.php
@@ -4,6 +4,9 @@
 
 use Laminas\Stdlib\AbstractOptions;
 
+/**
+ * @extends AbstractOptions<string|list<string>>
+ */
 class Envelope extends AbstractOptions
 {
     /** @var string|null */
diff --git a/src/Transport/FileOptions.php b/src/Transport/FileOptions.php
index 6f21cb87..8647ad1f 100644
--- a/src/Transport/FileOptions.php
+++ b/src/Transport/FileOptions.php
@@ -16,6 +16,9 @@
 use function sys_get_temp_dir;
 use function time;
 
+/**
+ * @extends AbstractOptions<string|callable>
+ */
 class FileOptions extends AbstractOptions
 {
     /** @var string Path to stored mail files */
diff --git a/src/Transport/SmtpOptions.php b/src/Transport/SmtpOptions.php
index 59984706..f2d2ef62 100644
--- a/src/Transport/SmtpOptions.php
+++ b/src/Transport/SmtpOptions.php
@@ -11,6 +11,9 @@
 use function is_string;
 use function sprintf;
 
+/**
+ * @extends AbstractOptions<string>
+ */
 class SmtpOptions extends AbstractOptions
 {
     /** @var string Local client hostname */
diff --git a/test/Header/HeaderWrapTest.php b/test/Header/HeaderWrapTest.php
index 3de8f249..15a7ccdd 100644
--- a/test/Header/HeaderWrapTest.php
+++ b/test/Header/HeaderWrapTest.php
@@ -29,7 +29,7 @@ public function testWrapUnstructuredHeaderAscii(): void
         $header = $this->createMock(UnstructuredInterface::class);
         $header->expects($this->any())
             ->method('getEncoding')
-            ->will($this->returnValue('ASCII'));
+            ->willReturn('ASCII');
         $expected = wordwrap($string, 78, "\r\n ");
 
         $test = HeaderWrap::wrap($string, $header);
@@ -45,7 +45,7 @@ public function testWrapUnstructuredHeaderMime(): void
         $header = $this->createMock(UnstructuredInterface::class);
         $header->expects($this->any())
             ->method('getEncoding')
-            ->will($this->returnValue('UTF-8'));
+            ->willReturn('UTF-8');
         $expected = "=?UTF-8?Q?foobarblahblahblah=20baz=20batfoobarblahblahblah=20baz=20?=\r\n"
                     . " =?UTF-8?Q?batfoobarblahblahblah=20baz=20bat?=";
 
diff --git a/test/Transport/SmtpTest.php b/test/Transport/SmtpTest.php
index 88895e80..2e05dfda 100644
--- a/test/Transport/SmtpTest.php
+++ b/test/Transport/SmtpTest.php
@@ -16,7 +16,6 @@
 use ReflectionClass;
 
 use function explode;
-use function sprintf;
 use function str_repeat;
 use function strlen;
 use function substr;
@@ -231,7 +230,7 @@ public function testLongLinesFoldingRFC5322(): void
         $this->assertCount(28, $lines);
 
         foreach ($lines as $line) {
-            $this->assertLessThanOrEqual($maxLen, strlen($line), sprintf('Line is too long: ' . $line));
+            $this->assertLessThanOrEqual($maxLen, strlen($line), 'Line is too long: ' . $line);
         }
 
         $this->assertStringNotContainsString(