diff --git a/.php_cs b/.php_cs
index ff29a34..56145ce 100644
--- a/.php_cs
+++ b/.php_cs
@@ -24,7 +24,7 @@ return PhpCsFixer\Config::create()
         'phpdoc_no_empty_return' => true,
         'phpdoc_order' => true,
         'phpdoc_scalar' => true,
-        'phpdoc_to_comment' => true,
+        'phpdoc_to_comment' => false,
         'phpdoc_summary' => true,
         'psr0' => true,
         'psr4' => true,
diff --git a/psalm.xml b/psalm.xml
index b22c0d5..ad6be53 100644
--- a/psalm.xml
+++ b/psalm.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0"?>
 <psalm
-    errorLevel="3"
+    errorLevel="1"
     resolveFromConfigFile="true"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns="https://getpsalm.org/schema/config"
diff --git a/src/Domain.php b/src/Domain.php
index b3a6ef8..f939d6c 100644
--- a/src/Domain.php
+++ b/src/Domain.php
@@ -45,7 +45,7 @@ final class Domain implements DomainName
     private const REGEXP_URI_DELIMITERS = '/[:\/?#\[\]@ ]/';
 
     /**
-     * @var array<string>
+     * @var array<int, string>
      */
     private array $labels;
 
@@ -176,7 +176,7 @@ private function domainToUnicode(string $domain): string
      */
     public function getIterator(): Iterator
     {
-        foreach ($this->labels as $offset => $label) {
+        foreach ($this->labels as $label) {
             yield $label;
         }
     }
@@ -216,7 +216,7 @@ public function label(int $key): ?string
     }
 
     /**
-     * @return array<int>
+     * @return list<int>
      */
     public function keys(string $label = null): array
     {
@@ -228,7 +228,7 @@ public function keys(string $label = null): array
     }
 
     /**
-     * @return array<string>
+     * @return array<int, string>
      */
     public function labels(): array
     {
@@ -274,7 +274,7 @@ public function toUnicode(): self
     /**
      * Filter a subdomain to update the domain part.
      *
-     * @param string|object $domain a domain
+     * @param string|object|null $domain a domain
      *
      * @throws TypeError if the domain can not be converted
      */
diff --git a/src/DomainName.php b/src/DomainName.php
index 2f45845..00496c2 100644
--- a/src/DomainName.php
+++ b/src/DomainName.php
@@ -36,7 +36,7 @@ public function label(int $key): ?string;
     /**
      * Returns the object labels.
      *
-     * @return array<string>
+     * @return array<int, string>
      */
     public function labels(): array;
 
@@ -63,7 +63,7 @@ public function getIterator(): Iterator;
      *
      * @see ::withLabel
      *
-     * @param mixed $label a domain label
+     * @param string|null|object $label a domain label
      */
     public function prepend($label): self;
 
@@ -72,7 +72,7 @@ public function prepend($label): self;
      *
      * @see ::withLabel
      *
-     * @param mixed $label a domain label
+     * @param string|null|object $label a domain label
      */
     public function append($label): self;
 
@@ -85,7 +85,7 @@ public function append($label): self;
      * If $key is non-negative, the added label will be the label at $key position from the start.
      * If $key is negative, the added label will be the label at $key position from the end.
      *
-     * @param mixed $label a domain label
+     * @param string|null|object $label a domain label
      *
      * @throws CannotProcessHost If the key is out of bounds
      * @throws CannotProcessHost If the label is converted to the NULL value
diff --git a/src/DomainTest.php b/src/DomainTest.php
index e8151db..1c32a14 100644
--- a/src/DomainTest.php
+++ b/src/DomainTest.php
@@ -338,7 +338,7 @@ public function testAppend(string $raw, string $append, string $expected): void
     }
 
     /**
-     * @return iterable<array{0:string, 1:string, 2:string}>
+     * @return iterable<array-key, array{0:string, 1:string, 2:string}>
      */
     public function validAppend(): iterable
     {
@@ -359,7 +359,7 @@ public function testPrepend(string $raw, string $prepend, string $expected): voi
     }
 
     /**
-     * @return iterable<array{0:string, 1:string, 2:string}>
+     * @return iterable<array-key, array{0:string, 1:string, 2:string}>
      */
     public function validPrepend(): iterable
     {
diff --git a/src/Idna.php b/src/Idna.php
index 30d859b..b7096c9 100644
--- a/src/Idna.php
+++ b/src/Idna.php
@@ -75,9 +75,14 @@ public static function toAscii(string $domain, int $options): IdnaInfo
 
         self::supportsIdna();
 
+        /**
+         * @param-out array{errors: int, isTransitionalDifferent: bool, result: string} $idnaInfo
+         */
         idn_to_ascii($domain, $options, INTL_IDNA_VARIANT_UTS46, $idnaInfo);
 
-        /* @var array{result:string, isTransitionalDifferent:bool, errors:int} $idnaInfo */
+        /**
+         * @var array{errors: int, isTransitionalDifferent: bool, result: string} $idnaInfo
+         */
         return self::createIdnaInfo($domain, $idnaInfo);
     }
 
@@ -96,9 +101,14 @@ public static function toUnicode(string $domain, int $options): IdnaInfo
 
         self::supportsIdna();
 
+        /**
+         * @param-out array{errors: int, isTransitionalDifferent: bool, result: string} $idnaInfo
+         */
         idn_to_utf8($domain, $options, INTL_IDNA_VARIANT_UTS46, $idnaInfo);
 
-        /* @var array{result:string, isTransitionalDifferent:bool, errors:int} $idnaInfo */
+        /**
+         * @var array{errors: int, isTransitionalDifferent: bool, result: string} $idnaInfo
+         */
         return self::createIdnaInfo($domain, $idnaInfo);
     }
 
diff --git a/src/ResolvedDomainTest.php b/src/ResolvedDomainTest.php
index 45f1a59..5a120fd 100644
--- a/src/ResolvedDomainTest.php
+++ b/src/ResolvedDomainTest.php
@@ -540,7 +540,7 @@ public function testWithSecondLevelDomain(
     }
 
     /**
-     * @return iterable<array{host:string|null, publicSuffix:string|null, sld:string|null, expectedSld:string|null, expectedHost:string|null}>
+     * @return iterable<array-key, array{host:string|null, publicSuffix:string|null, sld:string|null, expectedSld:string|null, expectedHost:string|null}>
      */
     public function withSldWorksProvider(): iterable
     {
diff --git a/src/Rules.php b/src/Rules.php
index 81b3ca2..6186f5a 100644
--- a/src/Rules.php
+++ b/src/Rules.php
@@ -157,7 +157,9 @@ private static function addRule(array $list, array $ruleParts): array
 
         $list[$rule] = $list[$rule] ?? ($isDomain ? [] : ['!' => '']);
         if ($isDomain && [] !== $ruleParts) {
-            $list[$rule] = self::addRule($list[$rule], $ruleParts);
+            /** @var array<array-key, array> $tmpList */
+            $tmpList = $list[$rule];
+            $list[$rule] = self::addRule($tmpList, $ruleParts);
         }
 
         return $list;
@@ -307,6 +309,7 @@ private function getEffectiveTopLevelDomainFromSection(DomainName $domain, strin
             }
 
             $matches[] = $label;
+            /** @var array<array-key, mixed> $rules */
             $rules = $rules[$label];
         }
 
diff --git a/src/Storage/TimeToLive.php b/src/Storage/TimeToLive.php
index 673a8f7..41b4682 100644
--- a/src/Storage/TimeToLive.php
+++ b/src/Storage/TimeToLive.php
@@ -58,10 +58,7 @@ public static function fromNow(DateTimeInterface $date): DateInterval
 
         $now = new DateTimeImmutable('NOW', $timezone);
 
-        /** @var DateInterval $diff */
-        $diff = $now->diff($date, false);
-
-        return $diff;
+        return $now->diff($date, false);
     }
 
     /**
diff --git a/src/TopLevelDomains.php b/src/TopLevelDomains.php
index 9974088..4623ad0 100644
--- a/src/TopLevelDomains.php
+++ b/src/TopLevelDomains.php
@@ -186,7 +186,7 @@ public function isEmpty(): bool
      */
     public function getIterator(): Iterator
     {
-        foreach ($this->records as $tld => $int) {
+        foreach ($this->records as $tld => $_) {
             yield $tld;
         }
     }