diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index cb1d5d45b0..2b0c61516e 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -58,6 +58,8 @@
     <rule ref="Squiz.PHP.DisallowInlineIf"/>
     <rule ref="Squiz.Scope.MethodScope"/>
     <rule ref="Squiz.Strings.ConcatenationSpacing"/>
+    <rule ref="Squiz.Strings.DoubleQuoteUsage.NotRequired"/>
+    <rule ref="Generic.Strings.UnnecessaryHeredoc"/>
     <rule ref="Squiz.WhiteSpace.ControlStructureSpacing"/>
     <rule ref="Squiz.WhiteSpace.FunctionClosingBraceSpace"/>
     <rule ref="Squiz.WhiteSpace.FunctionSpacing"/>
@@ -133,6 +135,7 @@
                 <element key="print" value="echo"/>
                 <element key="is_null" value="null"/>
                 <element key="create_function" value="null"/>
+                <element key="join" value="implode"/>
             </property>
         </properties>
     </rule>
@@ -150,7 +153,7 @@
 
     <!-- This test file specifically *needs* Windows line endings for testing purposes. -->
     <rule ref="Generic.Files.LineEndings.InvalidEOLChar">
-        <exclude-pattern>tests/Core/Tokenizers/PHP/StableCommentWhitespaceWinTest\.php</exclude-pattern>
+        <exclude-pattern>tests/Core/Tokenizers/PHP/*WinTest\.php</exclude-pattern>
     </rule>
 
     <!-- Avoid false positive with this sniff detecting itself -->
@@ -161,4 +164,7 @@
 
     <!-- Require visibility for class constants. -->
     <rule ref="PSR12.Properties.ConstantVisibility"/>
+
+    <!-- Handle consistent formatting of return types. -->
+    <rule ref="PSR12.Functions.ReturnTypeDeclaration"/>
 </ruleset>
diff --git a/src/Config.php b/src/Config.php
index ebd8e0511a..480abce696 100644
--- a/src/Config.php
+++ b/src/Config.php
@@ -1592,7 +1592,7 @@ public static function getExecutablePath(string $name)
             return $data;
         }
 
-        if ($name === "php") {
+        if ($name === 'php') {
             // For php, we know the executable path. There's no need to look it up.
             return PHP_BINARY;
         }
diff --git a/src/Files/File.php b/src/Files/File.php
index 84aaeba56a..99ab24097d 100644
--- a/src/Files/File.php
+++ b/src/Files/File.php
@@ -1229,7 +1229,7 @@ public function getFixedWarningCount()
      *
      * @return int
      */
-    public function getFirstRunCount(string $type):int
+    public function getFirstRunCount(string $type): int
     {
         return $this->firstRunCounts[$type];
 
diff --git a/src/Reports/Json.php b/src/Reports/Json.php
index 55fe4aa2ef..4447cbaef7 100644
--- a/src/Reports/Json.php
+++ b/src/Reports/Json.php
@@ -57,7 +57,7 @@ public function generateFileReport(array $report, File $phpcsFile, bool $showSou
                     $messagesObject->column  = $column;
                     $messagesObject->fixable = $fixable;
 
-                    $messages .= json_encode($messagesObject).",";
+                    $messages .= json_encode($messagesObject).',';
                 }
             }
         }//end foreach
@@ -99,7 +99,7 @@ public function generate(
     ) {
         echo '{"totals":{"errors":'.$totalErrors.',"warnings":'.$totalWarnings.',"fixable":'.$totalFixable.'},"files":{';
         echo rtrim($cachedData, ',');
-        echo "}}".PHP_EOL;
+        echo '}}'.PHP_EOL;
 
     }//end generate()
 
diff --git a/tests/Core/Ruleset/ExplainTest.php b/tests/Core/Ruleset/ExplainTest.php
index bb01e50abe..e74afe950b 100644
--- a/tests/Core/Ruleset/ExplainTest.php
+++ b/tests/Core/Ruleset/ExplainTest.php
@@ -179,7 +179,7 @@ public function testExplainCustomRuleset()
     public function testExplainWithDeprecatedSniffs()
     {
         // Set up the ruleset.
-        $standard = __DIR__."/ShowSniffDeprecationsTest.xml";
+        $standard = __DIR__.'/ShowSniffDeprecationsTest.xml';
         $config   = new ConfigDouble(["--standard=$standard", '-e']);
         $ruleset  = new Ruleset($config);
 
diff --git a/tests/Core/Ruleset/GetIgnorePatternsTest.php b/tests/Core/Ruleset/GetIgnorePatternsTest.php
index 23fe0532c9..ce185d3ead 100644
--- a/tests/Core/Ruleset/GetIgnorePatternsTest.php
+++ b/tests/Core/Ruleset/GetIgnorePatternsTest.php
@@ -37,7 +37,7 @@ final class GetIgnorePatternsTest extends TestCase
     public static function setUpBeforeClass(): void
     {
         // Set up the ruleset.
-        $standard      = __DIR__."/GetIgnorePatternsTest.xml";
+        $standard      = __DIR__.'/GetIgnorePatternsTest.xml';
         $config        = new ConfigDouble(["--standard=$standard"]);
         self::$ruleset = new Ruleset($config);
 
diff --git a/tests/Core/Ruleset/GetIncludePatternsTest.php b/tests/Core/Ruleset/GetIncludePatternsTest.php
index b67c189e11..5d32c446d2 100644
--- a/tests/Core/Ruleset/GetIncludePatternsTest.php
+++ b/tests/Core/Ruleset/GetIncludePatternsTest.php
@@ -37,7 +37,7 @@ final class GetIncludePatternsTest extends TestCase
     public static function setUpBeforeClass(): void
     {
         // Set up the ruleset.
-        $standard      = __DIR__."/GetIncludePatternsTest.xml";
+        $standard      = __DIR__.'/GetIncludePatternsTest.xml';
         $config        = new ConfigDouble(["--standard=$standard"]);
         self::$ruleset = new Ruleset($config);
 
diff --git a/tests/Core/Tokenizers/PHP/AttributesTest.php b/tests/Core/Tokenizers/PHP/AttributesTest.php
index 415971a98d..75d3b458f2 100644
--- a/tests/Core/Tokenizers/PHP/AttributesTest.php
+++ b/tests/Core/Tokenizers/PHP/AttributesTest.php
@@ -540,7 +540,7 @@ public static function dataAttributeOnTextLookingLikeCloseTag()
                     ],
                     [
                         'T_WHITESPACE',
-                        "    ",
+                        '    ',
                     ],
                     [
                         'T_CONSTANT_ENCAPSED_STRING',
diff --git a/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenMiscTest.php b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenMiscTest.php
index deae18e9a6..fbe95c4130 100644
--- a/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenMiscTest.php
+++ b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenMiscTest.php
@@ -33,7 +33,7 @@ public function testTabWidthNotSet()
         $config  = new ConfigDouble();
         $ruleset = new Ruleset($config);
 
-        $content   = <<<EOD
+        $content   = <<<'EOD'
 <?php
 		echo 'foo';
 EOD;
@@ -71,7 +71,7 @@ public function testLengthSettingRespectsEncoding()
         $config->tabWidth = 4;
         $ruleset          = new Ruleset($config);
 
-        $content   = <<<EOD
+        $content   = <<<'EOD'
 <?php
 echo 'пасха		пасха';
 EOD;
diff --git a/tests/Core/Util/Common/PrepareForOutputTest.php b/tests/Core/Util/Common/PrepareForOutputTest.php
index 3f4d595a4b..f9ad07af51 100644
--- a/tests/Core/Util/Common/PrepareForOutputTest.php
+++ b/tests/Core/Util/Common/PrepareForOutputTest.php
@@ -79,16 +79,16 @@ public static function dataPrepareForOutput()
                 'expectedWin' => "\\r\\n\\t",
             ],
             'Spaces are replaced with a unique mark'             => [
-                'content'     => "    ",
+                'content'     => '    ',
                 'exclude'     => [],
                 'expected'    => "\033[30;1m·\033[0m\033[30;1m·\033[0m\033[30;1m·\033[0m\033[30;1m·\033[0m",
-                'expectedWin' => "    ",
+                'expectedWin' => '    ',
             ],
             'Other characters are unaffected'                    => [
-                'content'     => "{echo 1;}",
+                'content'     => '{echo 1;}',
                 'exclude'     => [],
                 'expected'    => "{echo\033[30;1m·\033[0m1;}",
-                'expectedWin' => "{echo 1;}",
+                'expectedWin' => '{echo 1;}',
             ],
             'No replacements'                                    => [
                 'content'     => 'nothing-should-be-replaced',