diff --git a/src/Standards/PEAR/Sniffs/Functions/FunctionDeclarationSniff.php b/src/Standards/PEAR/Sniffs/Functions/FunctionDeclarationSniff.php
index bd59a7cd90..52fb1c1b9e 100644
--- a/src/Standards/PEAR/Sniffs/Functions/FunctionDeclarationSniff.php
+++ b/src/Standards/PEAR/Sniffs/Functions/FunctionDeclarationSniff.php
@@ -46,6 +46,7 @@ public function register()
         return [
             T_FUNCTION,
             T_CLOSURE,
+            T_FN,
         ];
 
     }//end register()
@@ -75,7 +76,9 @@ public function process(File $phpcsFile, $stackPtr)
         $openBracket  = $tokens[$stackPtr]['parenthesis_opener'];
         $closeBracket = $tokens[$stackPtr]['parenthesis_closer'];
 
-        if (strtolower($tokens[$stackPtr]['content']) === 'function') {
+        if (strtolower($tokens[$stackPtr]['content']) === 'function'
+            || strtolower($tokens[$stackPtr]['content']) === 'fn'
+        ) {
             // Must be one space after the FUNCTION keyword.
             if ($tokens[($stackPtr + 1)]['content'] === $phpcsFile->eolChar) {
                 $spaces = 'newline';
@@ -86,9 +89,13 @@ public function process(File $phpcsFile, $stackPtr)
             }
 
             if ($spaces !== 1) {
-                $error = 'Expected 1 space after FUNCTION keyword; %s found';
-                $data  = [$spaces];
-                $fix   = $phpcsFile->addFixableError($error, $stackPtr, 'SpaceAfterFunction', $data);
+                $error = 'Expected 1 space after %s keyword; %s found';
+                $data  = [
+                    strtoupper($tokens[$stackPtr]['content']),
+                    $spaces,
+                ];
+
+                $fix = $phpcsFile->addFixableError($error, $stackPtr, 'SpaceAfterFunction', $data);
                 if ($fix === true) {
                     if ($spaces === 0) {
                         $phpcsFile->fixer->addContent($stackPtr, ' ');
@@ -99,9 +106,9 @@ public function process(File $phpcsFile, $stackPtr)
             }
         }//end if
 
-        // Must be no space before the opening parenthesis. For closures, this is
-        // enforced by the previous check because there is no content between the keywords
-        // and the opening parenthesis.
+        // Must be no space before the opening parenthesis. For closures and arrow functions,
+        // this is enforced by the previous check because there is no content between
+        // the keywords and the opening parenthesis.
         // Unfinished closures are tokenized as T_FUNCTION however, and can be excluded
         // by checking for the scope_opener.
         if ($tokens[$stackPtr]['code'] === T_FUNCTION
@@ -257,6 +264,10 @@ public function isMultiLineDeclaration($phpcsFile, $stackPtr, $openBracket, $tok
      */
     public function processSingleLineDeclaration($phpcsFile, $stackPtr, $tokens)
     {
+        if ($tokens[$stackPtr]['code'] === T_FN) {
+            return;
+        }
+
         if ($tokens[$stackPtr]['code'] === T_CLOSURE) {
             $sniff = new OpeningFunctionBraceKernighanRitchieSniff();
         } else {
@@ -300,12 +311,20 @@ public function processMultiLineDeclaration($phpcsFile, $stackPtr, $tokens)
         // The opening brace needs to be one space away from the closing parenthesis.
         $opener = $tokens[$stackPtr]['scope_opener'];
         if ($tokens[$opener]['line'] !== $tokens[$closeBracket]['line']) {
-            $error = 'The closing parenthesis and the opening brace of a multi-line function declaration must be on the same line';
-            $fix   = $phpcsFile->addFixableError($error, $opener, 'NewlineBeforeOpenBrace');
+            $error = 'The closing parenthesis and the %s of a multi-line function declaration must be on the same line';
+            $code  = 'NewlineBeforeOpenBrace';
+            $data  = ['opening brace'];
+
+            if ($tokens[$stackPtr]['code'] === T_FN) {
+                $code = 'NewlineBeforeArrow';
+                $data = ['arrow'];
+            }
+
+            $fix = $phpcsFile->addFixableError($error, $opener, $code, $data);
             if ($fix === true) {
                 $prev = $phpcsFile->findPrevious(Tokens::$emptyTokens, ($opener - 1), $closeBracket, true);
                 $phpcsFile->fixer->beginChangeset();
-                $phpcsFile->fixer->addContent($prev, ' {');
+                $phpcsFile->fixer->addContent($prev, ' '.$tokens[$opener]['content']);
 
                 // If the opener is on a line by itself, removing it will create
                 // an empty line, so just remove the entire line instead.
@@ -340,8 +359,18 @@ public function processMultiLineDeclaration($phpcsFile, $stackPtr, $tokens)
             }
 
             if ($length !== 1) {
-                $error = 'There must be a single space between the closing parenthesis and the opening brace of a multi-line function declaration; found %s spaces';
-                $fix   = $phpcsFile->addFixableError($error, ($opener - 1), 'SpaceBeforeOpenBrace', [$length]);
+                $error = 'There must be a single space between the closing parenthesis and the %s of a multi-line function declaration; found %s spaces';
+                $code  = 'SpaceBeforeOpenBrace';
+                $data  = ['opening brace'];
+
+                if ($tokens[$stackPtr]['code'] === T_FN) {
+                    $code = 'SpaceBeforeArrow';
+                    $data = ['arrow'];
+                }
+
+                $data[] = $length;
+
+                $fix = $phpcsFile->addFixableError($error, ($opener - 1), $code, $data);
                 if ($fix === true) {
                     if ($length === 0) {
                         $phpcsFile->fixer->addContentBefore($opener, ' ');
diff --git a/src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.inc b/src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.inc
index 02e0a20dbf..4e3aa1ad32 100644
--- a/src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.inc
+++ b/src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.inc
@@ -418,3 +418,24 @@ class ConstructorPropertyPromotionMultiLineAttributesIncorrectIndent
         // Do something.
     }
 }
+
+$arrowNoArgs = fn () => $retrievedfromscope;
+
+$arrowSingleLineArgs = fn (Type $param1, int $param2, string $param3): \ReturnType => $retrievedfromscope;
+
+$arrowMultiLineArgs = fn (
+    $longVar1,
+    $longerVar2,
+    &...$muchLongerVar3
+) => $longVar1;
+
+$arrowNoArgs = fn(  )
+    => $retrievedfromscope;
+
+$arrowSingleLineArgs = fn( Type   $param1  ,   int   $param2, string $param3
+   )  : \ReturnType   => $retrievedfromscope;
+
+$arrowMultiLineArgs = fn (
+    $longVar1, $longerVar2,
+
+  & ...  $muchLongerVar3) => $longVar1;
diff --git a/src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.inc.fixed b/src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.inc.fixed
index 0d67e9f758..fa9281c575 100644
--- a/src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.inc.fixed
+++ b/src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.inc.fixed
@@ -416,3 +416,24 @@ class ConstructorPropertyPromotionMultiLineAttributesIncorrectIndent
         // Do something.
     }
 }
+
+$arrowNoArgs = fn () => $retrievedfromscope;
+
+$arrowSingleLineArgs = fn (Type $param1, int $param2, string $param3): \ReturnType => $retrievedfromscope;
+
+$arrowMultiLineArgs = fn (
+    $longVar1,
+    $longerVar2,
+    &...$muchLongerVar3
+) => $longVar1;
+
+$arrowNoArgs = fn (  )
+    => $retrievedfromscope;
+
+$arrowSingleLineArgs = fn ( Type   $param1  ,   int   $param2, string $param3
+)  : \ReturnType => $retrievedfromscope;
+
+$arrowMultiLineArgs = fn (
+    $longVar1, $longerVar2,
+    & ...  $muchLongerVar3
+) => $longVar1;
diff --git a/src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.php b/src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.php
index 01ab3e8482..210c60938b 100644
--- a/src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.php
+++ b/src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.php
@@ -99,6 +99,11 @@ public function getErrorList($testFile='FunctionDeclarationUnitTest.inc')
                 371 => 1,
                 402 => 1,
                 406 => 1,
+                432 => 1,
+                435 => 1,
+                436 => 2,
+                440 => 1,
+                441 => 2,
             ];
         } else {
             $errors = [