diff --git a/composer.json b/composer.json
index 09dd21b..9b33d6b 100644
--- a/composer.json
+++ b/composer.json
@@ -16,7 +16,7 @@
     "require": {
         "php": "^7.2",
         "dealerdirect/phpcodesniffer-composer-installer": "^0.4 || ^0.5",
-        "slevomat/coding-standard": "^5.0",
+        "slevomat/coding-standard": "dev-master",
         "squizlabs/php_codesniffer": "^3.3.2"
     },
     "require-dev": {
diff --git a/src/Libero/Sniffs/WhiteSpace/ObjectStaticOperatorSpacingSniff.php b/src/Libero/Sniffs/WhiteSpace/ObjectStaticOperatorSpacingSniff.php
index c1cf95b..78752dd 100644
--- a/src/Libero/Sniffs/WhiteSpace/ObjectStaticOperatorSpacingSniff.php
+++ b/src/Libero/Sniffs/WhiteSpace/ObjectStaticOperatorSpacingSniff.php
@@ -11,7 +11,10 @@
 
 final class ObjectStaticOperatorSpacingSniff extends BaseObjectOperatorSpacingSniff
 {
-    public function register()
+    /**
+     * @return array<int>
+     */
+    public function register() : array
     {
         return [T_DOUBLE_COLON];
     }
diff --git a/src/Libero/ruleset.xml b/src/Libero/ruleset.xml
index 3393832..3e46c06 100644
--- a/src/Libero/ruleset.xml
+++ b/src/Libero/ruleset.xml
@@ -27,10 +27,12 @@
     <rule ref="SlevomatCodingStandard.Classes.SuperfluousAbstractClassNaming"/>
     <rule ref="SlevomatCodingStandard.Classes.SuperfluousExceptionNaming"/>
     <rule ref="SlevomatCodingStandard.Classes.SuperfluousInterfaceNaming"/>
+    <rule ref="SlevomatCodingStandard.Commenting.RequireOneLinePropertyDocComment"/>
     <rule ref="SlevomatCodingStandard.ControlStructures.RequireNullCoalesceOperator"/>
     <rule ref="SlevomatCodingStandard.Namespaces.AlphabeticallySortedUses"/>
     <rule ref="SlevomatCodingStandard.Namespaces.ReferenceUsedNamesOnly">
         <properties>
+            <property name="searchAnnotations" value="true"/>
             <property name="allowFallbackGlobalConstants" value="false"/>
             <property name="allowFallbackGlobalFunctions" value="false"/>
         </properties>
@@ -54,6 +56,7 @@
             <property name="spacesCountAroundEqualsSign" value="0"/>
         </properties>
     </rule>
+    <rule ref="SlevomatCodingStandard.TypeHints.DisallowArrayTypeHintSyntax"/>
     <rule ref="SlevomatCodingStandard.TypeHints.NullableTypeForNullDefaultValue"/>
     <rule ref="SlevomatCodingStandard.TypeHints.ParameterTypeHintSpacing"/>
     <rule ref="SlevomatCodingStandard.TypeHints.ReturnTypeHintSpacing">
@@ -61,6 +64,15 @@
             <property name="spacesCountBeforeColon" value="1"/>
         </properties>
     </rule>
+    <rule ref="SlevomatCodingStandard.TypeHints.TypeHintDeclaration">
+        <properties>
+            <property name="allAnnotationsAreUseful" value="true"/>
+            <property name="enableEachParameterAndReturnInspection" value="true"/>
+            <property name="traversableTypeHints" type="array">
+                <element value="ArrayObject"/>
+            </property>
+        </properties>
+    </rule>
     <rule ref="Squiz.Classes.ClassFileName"/>
     <rule ref="Squiz.PHP.InnerFunctions"/>
     <rule ref="Squiz.Strings.DoubleQuoteUsage">
diff --git a/tests/RulesetTests.php b/tests/RulesetTests.php
index e323d15..4d16539 100644
--- a/tests/RulesetTests.php
+++ b/tests/RulesetTests.php
@@ -38,7 +38,7 @@ final class RulesetTests extends TestCase
     /** @var Runner */
     private static $codeSniffer;
 
-    public static function setUpBeforeClass()
+    public static function setUpBeforeClass() : void
     {
         self::$codeSniffer = new Runner();
         self::$codeSniffer->config = new Config(['--standard=Libero']);
@@ -48,6 +48,9 @@ public static function setUpBeforeClass()
     /**
      * @test
      * @dataProvider cases
+     *
+     * @param array<string> $messages
+     * @param array<string> $ignoreMessages
      */
     public function it_finds_and_fixes_violations(
         string $filename,
@@ -71,6 +74,9 @@ public function it_finds_and_fixes_violations(
         $this->assertSame($fixed, $file->fixer->getContents());
     }
 
+    /**
+     * @return iterable<string,array<mixed>>
+     */
     public function cases() : iterable
     {
         $files = Finder::create()->files()->in(__DIR__.'/cases');
@@ -174,6 +180,9 @@ private function createFile(string $filename, string $content) : File
         return $file;
     }
 
+    /**
+     * @return iterable<string>
+     */
     private function getMessages(File $file) : iterable
     {
         foreach ([$file->getErrors(), $file->getWarnings()] as $messages) {
diff --git a/tests/cases/classes/method-argument-type b/tests/cases/classes/method-argument-type
new file mode 100644
index 0000000..54078f5
--- /dev/null
+++ b/tests/cases/classes/method-argument-type
@@ -0,0 +1,45 @@
+---DESCRIPTION---
+Method argument types must be declared
+---FILENAME---
+Foo.php
+---CONTENTS---
+<?php
+
+declare(strict_types=1);
+
+namespace Vendor;
+
+use ArrayObject;
+
+class Foo
+{
+    public function bar($baz) : string
+    {
+    }
+
+    /**
+     * @param resource $quux
+     */
+    public function qux($quux) : string
+    {
+    }
+
+    public function quuz(array $corge) : string
+    {
+    }
+
+    public function grault(iterable $garply) : string
+    {
+    }
+
+    public function waldo(ArrayObject $fred) : string
+    {
+    }
+}
+
+---MESSAGES---
+11:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingParameterTypeHint
+22:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableParameterTypeHintSpecification
+26:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableParameterTypeHintSpecification
+30:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableParameterTypeHintSpecification
+---
diff --git a/tests/cases/classes/method-declaration b/tests/cases/classes/method-declaration
index cc68b91..1985857 100644
--- a/tests/cases/classes/method-declaration
+++ b/tests/cases/classes/method-declaration
@@ -11,6 +11,10 @@ namespace Vendor;
 
 class Foo
 {
+    /**
+     * @param resource $baz
+     * @param resource $qux
+     */
     public function bar  ( $baz  ,&$qux,  bool$quux, ? string  $quuz    =null   ,  string...$corge   ):
     void
     {
@@ -26,6 +30,10 @@ namespace Vendor;
 
 class Foo
 {
+    /**
+     * @param resource $baz
+     * @param resource $qux
+     */
     public function bar($baz, &$qux, bool $quux, ?string $quuz = null, string ...$corge) : void
     {
     }
diff --git a/tests/cases/classes/method-defaults b/tests/cases/classes/method-defaults
index 6ca4165..3d40f06 100644
--- a/tests/cases/classes/method-defaults
+++ b/tests/cases/classes/method-defaults
@@ -11,11 +11,11 @@ namespace Vendor;
 
 class Foo
 {
-    public function bar($baz = [], $qux) : void
+    public function bar(string $baz = '', string $qux) : void
     {
     }
 }
 
 ---MESSAGES---
-9:36 PEAR.Functions.ValidDefaultValue.NotAtEnd
+9:50 PEAR.Functions.ValidDefaultValue.NotAtEnd
 ---
diff --git a/tests/cases/classes/method-return-type b/tests/cases/classes/method-return-type
new file mode 100644
index 0000000..fc31504
--- /dev/null
+++ b/tests/cases/classes/method-return-type
@@ -0,0 +1,126 @@
+---DESCRIPTION---
+Method return types must be declared
+---FILENAME---
+Foo.php
+---CONTENTS---
+<?php
+
+declare(strict_types=1);
+
+namespace Vendor;
+
+use ArrayObject;
+
+class Foo
+{
+    public function bar() : string
+    {
+    }
+
+    /**
+     * @return resource
+     */
+    public function baz()
+    {
+    }
+
+    public function qux()
+    {
+    }
+
+    public function quux()
+    {
+        return 'quuz';
+    }
+
+    public function quuz() : array
+    {
+    }
+
+    public function corge() : iterable
+    {
+    }
+
+    /**
+     * @return string[]
+     */
+    public function grault() : array
+    {
+    }
+
+    /**
+     * @return string[]
+     */
+    public function garply() : iterable
+    {
+    }
+
+    public function waldo() : ArrayObject
+    {
+    }
+}
+
+---FIXED---
+<?php
+
+declare(strict_types=1);
+
+namespace Vendor;
+
+use ArrayObject;
+
+class Foo
+{
+    public function bar() : string
+    {
+    }
+
+    /**
+     * @return resource
+     */
+    public function baz()
+    {
+    }
+
+    public function qux() : void
+    {
+    }
+
+    public function quux()
+    {
+        return 'quuz';
+    }
+
+    public function quuz() : array
+    {
+    }
+
+    public function corge() : iterable
+    {
+    }
+
+    /**
+     * @return array<string>
+     */
+    public function grault() : array
+    {
+    }
+
+    /**
+     * @return iterable<string>
+     */
+    public function garply() : iterable
+    {
+    }
+
+    public function waldo() : ArrayObject
+    {
+    }
+}
+
+---MESSAGES---
+26:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingReturnTypeHint
+31:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableReturnTypeHintSpecification
+35:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableReturnTypeHintSpecification
+53:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableReturnTypeHintSpecification
+---
diff --git a/tests/cases/classes/method-type-case b/tests/cases/classes/method-type-case
index 00bd37e..d8286cf 100644
--- a/tests/cases/classes/method-type-case
+++ b/tests/cases/classes/method-type-case
@@ -11,10 +11,16 @@ namespace Vendor;
 
 abstract class Foo
 {
+    /**
+     * @param array<string> $qux
+     */
     public function bar(String $baz, ARRAY $qux) : vOiD
     {
     }
 
+    /**
+     * @return iterable<string>
+     */
     abstract public function quux(Bool $quuz, OBJECT $corge) : iTeRaBlE;
 }
 
@@ -27,10 +33,16 @@ namespace Vendor;
 
 abstract class Foo
 {
+    /**
+     * @param array<string> $qux
+     */
     public function bar(string $baz, array $qux) : void
     {
     }
 
+    /**
+     * @return iterable<string>
+     */
     abstract public function quux(bool $quuz, object $corge) : iterable;
 }
 
diff --git a/tests/cases/classes/property-single b/tests/cases/classes/property-single
index df3adb9..b2f9661 100644
--- a/tests/cases/classes/property-single
+++ b/tests/cases/classes/property-single
@@ -11,9 +11,10 @@ namespace Vendor;
 
 class Foo
 {
+    /** @var string */
     public $bar, $baz;
 }
 
 ---MESSAGES---
-9:12 PSR2.Classes.PropertyDeclaration.Multiple
+10:12 PSR2.Classes.PropertyDeclaration.Multiple
 ---
diff --git a/tests/cases/classes/property-type b/tests/cases/classes/property-type
new file mode 100644
index 0000000..c87c2dd
--- /dev/null
+++ b/tests/cases/classes/property-type
@@ -0,0 +1,64 @@
+---DESCRIPTION---
+Property types must be declared
+---FILENAME---
+Foo.php
+---CONTENTS---
+<?php
+
+declare(strict_types=1);
+
+namespace Vendor;
+
+use ArrayObject;
+
+class Foo
+{
+    public $bar;
+
+    /**
+     * @var string
+     */
+    public $baz;
+
+    /** @var array */
+    public $qux;
+
+    /** @var iterable */
+    public $quux;
+
+    /** @var ArrayObject */
+    public $quuz;
+}
+
+---FIXED---
+<?php
+
+declare(strict_types=1);
+
+namespace Vendor;
+
+use ArrayObject;
+
+class Foo
+{
+    public $bar;
+
+    /** @var string */
+    public $baz;
+
+    /** @var array */
+    public $qux;
+
+    /** @var iterable */
+    public $quux;
+
+    /** @var ArrayObject */
+    public $quuz;
+}
+
+---MESSAGES---
+11:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingPropertyTypeHint
+16:9 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversablePropertyTypeHintSpecification
+19:9 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversablePropertyTypeHintSpecification
+22:9 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversablePropertyTypeHintSpecification
+---
diff --git a/tests/cases/classes/property-underscore b/tests/cases/classes/property-underscore
index a069a7b..8ea4a44 100644
--- a/tests/cases/classes/property-underscore
+++ b/tests/cases/classes/property-underscore
@@ -11,9 +11,10 @@ namespace Vendor;
 
 class Foo
 {
+    /** @var string */
     private $_bar;
 }
 
 ---MESSAGES---
-9:13 PSR2.Classes.PropertyDeclaration.Underscore
+10:13 PSR2.Classes.PropertyDeclaration.Underscore
 ---
diff --git a/tests/cases/classes/property-visibility b/tests/cases/classes/property-visibility
index fb9d1ff..c300007 100644
--- a/tests/cases/classes/property-visibility
+++ b/tests/cases/classes/property-visibility
@@ -11,11 +11,12 @@ namespace Vendor;
 
 class Foo
 {
+    /** @var string */
     var $bar;
 }
 
 ---MESSAGES---
-9:9 PSR2.Classes.PropertyDeclaration.ScopeMissing
+10:9 PSR2.Classes.PropertyDeclaration.ScopeMissing
 ---IGNORE-MESSAGES---
-9:9 PSR2.Classes.PropertyDeclaration.VarUsed
+10:9 PSR2.Classes.PropertyDeclaration.VarUsed
 ---
diff --git a/tests/cases/closures/declaration b/tests/cases/closures/declaration
index f355a87..206c55d 100644
--- a/tests/cases/closures/declaration
+++ b/tests/cases/closures/declaration
@@ -7,11 +7,19 @@ declare(strict_types=1);
 
 namespace Vendor;
 
+/**
+ * @param resource $bar
+ * @param resource $baz
+ */
 $foo = function   ( $bar  ,&$baz,  bool$qux, ? string  $quux    =null   ,  string...$quuz   )use  ( &$foo)   :
 void
 {
 };
 
+/**
+ * @param resource $grault
+ * @param resource $garply
+ */
 $corge = function
 ( $grault  ,$garply,
       bool$waldo, ? string  $fred    =null   )   use( $foo,&$corge
@@ -27,9 +35,17 @@ declare(strict_types=1);
 
 namespace Vendor;
 
+/**
+ * @param resource $bar
+ * @param resource $baz
+ */
 $foo = function ($bar, &$baz, bool $qux, ?string $quux = null, string ...$quuz) use (&$foo) : void {
 };
 
+/**
+ * @param resource $grault
+ * @param resource $garply
+ */
 $corge = function (
     $grault,
     $garply,
diff --git a/tests/cases/closures/defaults b/tests/cases/closures/defaults
index ad666ab..f7c72b1 100644
--- a/tests/cases/closures/defaults
+++ b/tests/cases/closures/defaults
@@ -7,9 +7,9 @@ declare(strict_types=1);
 
 namespace Vendor;
 
-$foo = function ($bar = [], $baz) : void {
+$foo = function (string $bar = '', string $baz) : void {
 };
 
 ---MESSAGES---
-7:29 PEAR.Functions.ValidDefaultValue.NotAtEnd
+7:43 PEAR.Functions.ValidDefaultValue.NotAtEnd
 ---
diff --git a/tests/cases/functions/declaration b/tests/cases/functions/declaration
index e3882e4..ce088ef 100644
--- a/tests/cases/functions/declaration
+++ b/tests/cases/functions/declaration
@@ -7,11 +7,19 @@ declare(strict_types=1);
 
 namespace Vendor;
 
+/**
+ * @param resource $bar
+ * @param resource $baz
+ */
 function foo  ( $bar  ,&$baz,  bool$qux, ? string  $quux    =null   ,  string...$quuz   ):
 void
 {
 }
 
+/**
+ * @param resource $grault
+ * @param resource $garply
+ */
 function corge
 ( $grault  ,$garply,
       bool$waldo, ? string  $fred    =null   ):void
@@ -25,10 +33,18 @@ declare(strict_types=1);
 
 namespace Vendor;
 
+/**
+ * @param resource $bar
+ * @param resource $baz
+ */
 function foo($bar, &$baz, bool $qux, ?string $quux = null, string ...$quuz) : void
 {
 }
 
+/**
+ * @param resource $grault
+ * @param resource $garply
+ */
 function corge(
     $grault,
     $garply,
diff --git a/tests/cases/functions/defaults b/tests/cases/functions/defaults
index febfc22..5a9ec62 100644
--- a/tests/cases/functions/defaults
+++ b/tests/cases/functions/defaults
@@ -7,10 +7,10 @@ declare(strict_types=1);
 
 namespace Vendor;
 
-function foo($bar = [], $baz)
+function foo(string $bar = '', string $baz) : void
 {
 }
 
 ---MESSAGES---
-7:25 PEAR.Functions.ValidDefaultValue.NotAtEnd
+7:39 PEAR.Functions.ValidDefaultValue.NotAtEnd
 ---
diff --git a/tests/cases/functions/return-type b/tests/cases/functions/return-type
new file mode 100644
index 0000000..703b378
--- /dev/null
+++ b/tests/cases/functions/return-type
@@ -0,0 +1,110 @@
+---DESCRIPTION---
+Function return types must be declared
+---CONTENTS---
+<?php
+
+declare(strict_types=1);
+
+function foo() : string
+{
+}
+
+/**
+ * @return resource
+ */
+function bar()
+{
+}
+
+function baz()
+{
+}
+
+function qux()
+{
+    return 'quz';
+}
+
+function quuz() : array
+{
+}
+
+function corge() : iterable
+{
+}
+
+/**
+ * @return string[]
+ */
+function grault() : array
+{
+}
+
+/**
+ * @return string[]
+ */
+function garply() : iterable
+{
+}
+
+function waldo() : ArrayObject
+{
+}
+
+---FIXED---
+<?php
+
+declare(strict_types=1);
+
+function foo() : string
+{
+}
+
+/**
+ * @return resource
+ */
+function bar()
+{
+}
+
+function baz() : void
+{
+}
+
+function qux()
+{
+    return 'quz';
+}
+
+function quuz() : array
+{
+}
+
+function corge() : iterable
+{
+}
+
+/**
+ * @return array<string>
+ */
+function grault() : array
+{
+}
+
+/**
+ * @return iterable<string>
+ */
+function garply() : iterable
+{
+}
+
+function waldo() : ArrayObject
+{
+}
+
+---MESSAGES---
+20:1 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingReturnTypeHint
+25:1 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableReturnTypeHintSpecification
+29:1 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableReturnTypeHintSpecification
+47:1 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableReturnTypeHintSpecification
+---
diff --git a/tests/cases/functions/type-case b/tests/cases/functions/type-case
index f304a6f..cb1e4d5 100644
--- a/tests/cases/functions/type-case
+++ b/tests/cases/functions/type-case
@@ -5,10 +5,16 @@ Primitive types must be in lower case
 
 declare(strict_types=1);
 
+/**
+ * @param array<string> $baz
+ */
 function foo(String $bar, ARRAY $baz) : vOiD
 {
 }
 
+/**
+ * @return iterable<string>
+ */
 function qux(Bool $quux, OBJECT $quuz) : iTeRaBlE
 {
 }
@@ -18,10 +24,16 @@ function qux(Bool $quux, OBJECT $quuz) : iTeRaBlE
 
 declare(strict_types=1);
 
+/**
+ * @param array<string> $baz
+ */
 function foo(string $bar, array $baz) : void
 {
 }
 
+/**
+ * @return iterable<string>
+ */
 function qux(bool $quux, object $quuz) : iterable
 {
 }
diff --git a/tests/cases/interfaces/method-argument-type b/tests/cases/interfaces/method-argument-type
new file mode 100644
index 0000000..ca37432
--- /dev/null
+++ b/tests/cases/interfaces/method-argument-type
@@ -0,0 +1,35 @@
+---DESCRIPTION---
+Method argument types must be declared
+---FILENAME---
+Foo.php
+---CONTENTS---
+<?php
+
+declare(strict_types=1);
+
+namespace Vendor;
+
+use ArrayObject;
+
+interface Foo
+{
+    public function bar($baz) : string;
+
+    /**
+     * @param resource $quux
+     */
+    public function qux($quux) : string;
+
+    public function quuz(array $corge) : string;
+
+    public function grault(iterable $garply) : string;
+
+    public function waldo(ArrayObject $fred) : string;
+}
+
+---MESSAGES---
+11:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingParameterTypeHint
+18:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableParameterTypeHintSpecification
+20:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableParameterTypeHintSpecification
+22:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableParameterTypeHintSpecification
+---
diff --git a/tests/cases/interfaces/method-defaults b/tests/cases/interfaces/method-defaults
index 1fc27e0..f210157 100644
--- a/tests/cases/interfaces/method-defaults
+++ b/tests/cases/interfaces/method-defaults
@@ -11,9 +11,9 @@ namespace Vendor;
 
 interface Foo
 {
-    public function bar($baz = [], $qux);
+    public function bar(string $baz = '', string $qux) : void;
 }
 
 ---MESSAGES---
-9:36 PEAR.Functions.ValidDefaultValue.NotAtEnd
+9:50 PEAR.Functions.ValidDefaultValue.NotAtEnd
 ---
diff --git a/tests/cases/interfaces/method-return-type b/tests/cases/interfaces/method-return-type
new file mode 100644
index 0000000..6756750
--- /dev/null
+++ b/tests/cases/interfaces/method-return-type
@@ -0,0 +1,83 @@
+---DESCRIPTION---
+Method return types must be declared
+---FILENAME---
+Foo.php
+---CONTENTS---
+<?php
+
+declare(strict_types=1);
+
+namespace Vendor;
+
+use ArrayObject;
+
+interface Foo
+{
+    public function bar() : string;
+
+    /**
+     * @return resource
+     */
+    public function baz();
+
+    public function qux();
+
+    public function quux() : array;
+
+    public function quuz() : iterable;
+
+    /**
+     * @return string[]
+     */
+    public function corge() : array;
+
+    /**
+     * @return string[]
+     */
+    public function grault() : iterable;
+
+    public function garply() : ArrayObject;
+}
+
+---FIXED---
+<?php
+
+declare(strict_types=1);
+
+namespace Vendor;
+
+use ArrayObject;
+
+interface Foo
+{
+    public function bar() : string;
+
+    /**
+     * @return resource
+     */
+    public function baz();
+
+    public function qux() : void;
+
+    public function quux() : array;
+
+    public function quuz() : iterable;
+
+    /**
+     * @return array<string>
+     */
+    public function corge() : array;
+
+    /**
+     * @return iterable<string>
+     */
+    public function grault() : iterable;
+
+    public function garply() : ArrayObject;
+}
+
+---MESSAGES---
+20:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableReturnTypeHintSpecification
+22:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableReturnTypeHintSpecification
+34:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableReturnTypeHintSpecification
+---
diff --git a/tests/cases/interfaces/method-type-case b/tests/cases/interfaces/method-type-case
index 4d143c8..2eeda17 100644
--- a/tests/cases/interfaces/method-type-case
+++ b/tests/cases/interfaces/method-type-case
@@ -11,8 +11,14 @@ namespace Vendor;
 
 interface Foo
 {
+    /**
+     * @param array<string> $qux
+     */
     public function bar(String $baz, ARRAY $qux) : vOiD;
 
+    /**
+     * @return iterable<string>
+     */
     public function quux(Bool $quuz, OBJECT $corge) : iTeRaBlE;
 }
 
@@ -25,8 +31,14 @@ namespace Vendor;
 
 interface Foo
 {
+    /**
+     * @param array<string> $qux
+     */
     public function bar(string $baz, array $qux) : void;
 
+    /**
+     * @return iterable<string>
+     */
     public function quux(bool $quuz, object $corge) : iterable;
 }
 
diff --git a/tests/cases/php/short-arrays b/tests/cases/php/short-arrays
index 04d3fd5..4c7465d 100644
--- a/tests/cases/php/short-arrays
+++ b/tests/cases/php/short-arrays
@@ -11,7 +11,7 @@ $baz = array(
     'qux',
 );
 
-$quux = function (array $quuz = array()) {
+$quux = function (array $quuz = array()) : void {
 };
 
 ---FIXED---
@@ -25,7 +25,7 @@ $baz = [
     'qux',
 ];
 
-$quux = function (array $quuz = []) {
+$quux = function (array $quuz = []) : void {
 };
 
 ---
diff --git a/tests/cases/trait/method-argument-type b/tests/cases/trait/method-argument-type
new file mode 100644
index 0000000..9657113
--- /dev/null
+++ b/tests/cases/trait/method-argument-type
@@ -0,0 +1,45 @@
+---DESCRIPTION---
+Method argument types must be declared
+---FILENAME---
+Foo.php
+---CONTENTS---
+<?php
+
+declare(strict_types=1);
+
+namespace Vendor;
+
+use ArrayObject;
+
+trait Foo
+{
+    public function bar($baz) : string
+    {
+    }
+
+    /**
+     * @param resource $quux
+     */
+    public function qux($quux) : string
+    {
+    }
+
+    public function quuz(array $corge) : string
+    {
+    }
+
+    public function grault(iterable $garply) : string
+    {
+    }
+
+    public function waldo(ArrayObject $fred) : string
+    {
+    }
+}
+
+---MESSAGES---
+11:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingParameterTypeHint
+22:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableParameterTypeHintSpecification
+26:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableParameterTypeHintSpecification
+30:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableParameterTypeHintSpecification
+---
diff --git a/tests/cases/trait/method-declaration b/tests/cases/trait/method-declaration
index dc6b1e9..7337668 100644
--- a/tests/cases/trait/method-declaration
+++ b/tests/cases/trait/method-declaration
@@ -11,6 +11,10 @@ namespace Vendor;
 
 trait Foo
 {
+    /**
+     * @param resource $baz
+     * @param resource $qux
+     */
     public function bar  ( $baz  ,&$qux,  bool$quux, ? string  $quuz    =null   ,  string...$corge   ):
     void
     {
@@ -26,6 +30,10 @@ namespace Vendor;
 
 trait Foo
 {
+    /**
+     * @param resource $baz
+     * @param resource $qux
+     */
     public function bar($baz, &$qux, bool $quux, ?string $quuz = null, string ...$corge) : void
     {
     }
diff --git a/tests/cases/trait/method-defaults b/tests/cases/trait/method-defaults
index 9218dc0..34372bf 100644
--- a/tests/cases/trait/method-defaults
+++ b/tests/cases/trait/method-defaults
@@ -11,11 +11,11 @@ namespace Vendor;
 
 trait Foo
 {
-    public function bar($baz = [], $qux) : void
+    public function bar(string $baz = '', string $qux) : void
     {
     }
 }
 
 ---MESSAGES---
-9:36 PEAR.Functions.ValidDefaultValue.NotAtEnd
+9:50 PEAR.Functions.ValidDefaultValue.NotAtEnd
 ---
diff --git a/tests/cases/trait/method-return-type b/tests/cases/trait/method-return-type
new file mode 100644
index 0000000..6d70155
--- /dev/null
+++ b/tests/cases/trait/method-return-type
@@ -0,0 +1,126 @@
+---DESCRIPTION---
+Method return types must be declared
+---FILENAME---
+Foo.php
+---CONTENTS---
+<?php
+
+declare(strict_types=1);
+
+namespace Vendor;
+
+use ArrayObject;
+
+trait Foo
+{
+    public function bar() : string
+    {
+    }
+
+    /**
+     * @return resource
+     */
+    public function baz()
+    {
+    }
+
+    public function qux()
+    {
+    }
+
+    public function quux()
+    {
+        return 'quuz';
+    }
+
+    public function quuz() : array
+    {
+    }
+
+    public function corge() : iterable
+    {
+    }
+
+    /**
+     * @return string[]
+     */
+    public function grault() : array
+    {
+    }
+
+    /**
+     * @return string[]
+     */
+    public function garply() : iterable
+    {
+    }
+
+    public function waldo() : ArrayObject
+    {
+    }
+}
+
+---FIXED---
+<?php
+
+declare(strict_types=1);
+
+namespace Vendor;
+
+use ArrayObject;
+
+trait Foo
+{
+    public function bar() : string
+    {
+    }
+
+    /**
+     * @return resource
+     */
+    public function baz()
+    {
+    }
+
+    public function qux() : void
+    {
+    }
+
+    public function quux()
+    {
+        return 'quuz';
+    }
+
+    public function quuz() : array
+    {
+    }
+
+    public function corge() : iterable
+    {
+    }
+
+    /**
+     * @return array<string>
+     */
+    public function grault() : array
+    {
+    }
+
+    /**
+     * @return iterable<string>
+     */
+    public function garply() : iterable
+    {
+    }
+
+    public function waldo() : ArrayObject
+    {
+    }
+}
+
+---MESSAGES---
+26:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingReturnTypeHint
+31:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableReturnTypeHintSpecification
+35:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableReturnTypeHintSpecification
+53:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableReturnTypeHintSpecification
+---
diff --git a/tests/cases/trait/method-type-case b/tests/cases/trait/method-type-case
index ab93bb2..a167c75 100644
--- a/tests/cases/trait/method-type-case
+++ b/tests/cases/trait/method-type-case
@@ -11,10 +11,16 @@ namespace Vendor;
 
 trait Foo
 {
+    /**
+     * @param array<string> $qux
+     */
     public function bar(String $baz, ARRAY $qux) : vOiD
     {
     }
 
+    /**
+     * @return iterable<string>
+     */
     abstract public function quux(Bool $quuz, OBJECT $corge) : iTeRaBlE;
 }
 
@@ -27,10 +33,16 @@ namespace Vendor;
 
 trait Foo
 {
+    /**
+     * @param array<string> $qux
+     */
     public function bar(string $baz, array $qux) : void
     {
     }
 
+    /**
+     * @return iterable<string>
+     */
     abstract public function quux(bool $quuz, object $corge) : iterable;
 }
 
diff --git a/tests/cases/trait/property-single b/tests/cases/trait/property-single
index e2d53c5..60ac03d 100644
--- a/tests/cases/trait/property-single
+++ b/tests/cases/trait/property-single
@@ -11,9 +11,10 @@ namespace Vendor;
 
 trait Foo
 {
+    /** @var string */
     public $bar, $baz;
 }
 
 ---MESSAGES---
-9:12 PSR2.Classes.PropertyDeclaration.Multiple
+10:12 PSR2.Classes.PropertyDeclaration.Multiple
 ---
diff --git a/tests/cases/trait/property-type b/tests/cases/trait/property-type
new file mode 100644
index 0000000..2fc8e1b
--- /dev/null
+++ b/tests/cases/trait/property-type
@@ -0,0 +1,64 @@
+---DESCRIPTION---
+Property types must be declared
+---FILENAME---
+Foo.php
+---CONTENTS---
+<?php
+
+declare(strict_types=1);
+
+namespace Vendor;
+
+use ArrayObject;
+
+trait Foo
+{
+    public $bar;
+
+    /**
+     * @var string
+     */
+    public $baz;
+
+    /** @var array */
+    public $qux;
+
+    /** @var iterable */
+    public $quux;
+
+    /** @var ArrayObject */
+    public $quuz;
+}
+
+---FIXED---
+<?php
+
+declare(strict_types=1);
+
+namespace Vendor;
+
+use ArrayObject;
+
+trait Foo
+{
+    public $bar;
+
+    /** @var string */
+    public $baz;
+
+    /** @var array */
+    public $qux;
+
+    /** @var iterable */
+    public $quux;
+
+    /** @var ArrayObject */
+    public $quuz;
+}
+
+---MESSAGES---
+11:12 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingPropertyTypeHint
+16:9 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversablePropertyTypeHintSpecification
+19:9 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversablePropertyTypeHintSpecification
+22:9 SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversablePropertyTypeHintSpecification
+---
diff --git a/tests/cases/trait/property-underscore b/tests/cases/trait/property-underscore
index 1279a6b..ec7e59a 100644
--- a/tests/cases/trait/property-underscore
+++ b/tests/cases/trait/property-underscore
@@ -11,9 +11,10 @@ namespace Vendor;
 
 trait Foo
 {
+    /** @var string */
     private $_bar;
 }
 
 ---MESSAGES---
-9:13 PSR2.Classes.PropertyDeclaration.Underscore
+10:13 PSR2.Classes.PropertyDeclaration.Underscore
 ---
diff --git a/tests/cases/trait/property-visibility b/tests/cases/trait/property-visibility
index fc0c068..fe1f567 100644
--- a/tests/cases/trait/property-visibility
+++ b/tests/cases/trait/property-visibility
@@ -11,11 +11,12 @@ namespace Vendor;
 
 trait Foo
 {
+    /** @var string */
     var $bar;
 }
 
 ---MESSAGES---
-9:9 PSR2.Classes.PropertyDeclaration.ScopeMissing
+10:9 PSR2.Classes.PropertyDeclaration.ScopeMissing
 ---IGNORE-MESSAGES---
-9:9 PSR2.Classes.PropertyDeclaration.VarUsed
+10:9 PSR2.Classes.PropertyDeclaration.VarUsed
 ---
diff --git a/tests/cases/whitespace/indentation b/tests/cases/whitespace/indentation
index 0612cec..30b9895 100644
--- a/tests/cases/whitespace/indentation
+++ b/tests/cases/whitespace/indentation
@@ -5,10 +5,10 @@
 
 declare(strict_types=1);
 
-function foo(array $bar) : iterable
+function foo() : void
    {
- foreach ($bar as $baz) {
-yield $baz;
+ foreach ([] as $bar) {
+echo $bar;
  }
   }
 
@@ -17,10 +17,10 @@ yield $baz;
 
 declare(strict_types=1);
 
-function foo(array $bar) : iterable
+function foo() : void
 {
-    foreach ($bar as $baz) {
-        yield $baz;
+    foreach ([] as $bar) {
+        echo $bar;
     }
 }
 
diff --git a/tests/cases/whitespace/tabs b/tests/cases/whitespace/tabs
index 7674045..df75a9b 100644
--- a/tests/cases/whitespace/tabs
+++ b/tests/cases/whitespace/tabs
@@ -5,10 +5,10 @@ Must use spaces not tabs
 
 declare(strict_types=1);
 
-function foo(array $bar) : iterable
+function foo() : void
 {
-	foreach ($bar as $baz) {
-		yield $baz;
+	foreach ([] as $bar) {
+		echo $bar;
 	}
 }
 
@@ -17,10 +17,10 @@ function foo(array $bar) : iterable
 
 declare(strict_types=1);
 
-function foo(array $bar) : iterable
+function foo() : void
 {
-    foreach ($bar as $baz) {
-        yield $baz;
+    foreach ([] as $bar) {
+        echo $bar;
     }
 }
 
diff --git a/tests/cases/whitespace/trailing b/tests/cases/whitespace/trailing
index d34ee81..4ca3ec0 100644
--- a/tests/cases/whitespace/trailing
+++ b/tests/cases/whitespace/trailing
@@ -5,10 +5,10 @@ Must not have trailing whitespace
   
 declare(strict_types=1);   
     
-function foo(array $bar) : iterable     
+function foo() : void     
 {      
-    foreach ($bar as $baz) {       
-        yield $baz;        
+    foreach ([] as $bar) {       
+        echo $bar;        
     }         
 }          
            
@@ -17,10 +17,10 @@ function foo(array $bar) : iterable
 
 declare(strict_types=1);
 
-function foo(array $bar) : iterable
+function foo() : void
 {
-    foreach ($bar as $baz) {
-        yield $baz;
+    foreach ([] as $bar) {
+        echo $bar;
     }
 }