diff --git a/src/Symfony/Component/String/AbstractUnicodeString.php b/src/Symfony/Component/String/AbstractUnicodeString.php
index 21aa22e186a64..2861b38d7bb1f 100644
--- a/src/Symfony/Component/String/AbstractUnicodeString.php
+++ b/src/Symfony/Component/String/AbstractUnicodeString.php
@@ -366,8 +366,23 @@ public function reverse(): parent
 
     public function snake(): parent
     {
-        $str = $this->camel();
-        $str->string = mb_strtolower(preg_replace(['/(\p{Lu}+)(\p{Lu}\p{Ll})/u', '/([\p{Ll}0-9])(\p{Lu})/u'], '\1_\2', $str->string), 'UTF-8');
+        $str = clone $this;
+        $matches = [];
+
+        preg_match_all(
+            '/([\p{Ll}0-9]+(?=\p{Lu}))|(\p{Lu}[\p{Ll}0-9]+)|(\p{Lu}+(?=\p{Lu}\p{Ll}))|((?<=\w)?[\p{Ll}\p{Lu}0-9]+(?=\w)?)/u',
+            $str->string,
+            $matches
+        );
+
+        $strings = array_map(
+            function (string $matchedString) {
+                return mb_strtolower($matchedString, 'UTF-8');
+            },
+            $matches[0] ?? []
+        );
+
+        $str->string = implode('_', $strings);
 
         return $str;
     }
diff --git a/src/Symfony/Component/String/ByteString.php b/src/Symfony/Component/String/ByteString.php
index 05170da801c0e..667ca16e4b149 100644
--- a/src/Symfony/Component/String/ByteString.php
+++ b/src/Symfony/Component/String/ByteString.php
@@ -366,8 +366,23 @@ public function slice(int $start = 0, ?int $length = null): parent
 
     public function snake(): parent
     {
-        $str = $this->camel();
-        $str->string = strtolower(preg_replace(['/([A-Z]+)([A-Z][a-z])/', '/([a-z\d])([A-Z])/'], '\1_\2', $str->string));
+        $str = clone $this;
+        $matches = [];
+
+        preg_match_all(
+            '/([a-z0-9]+(?=[A-Z]))|([A-Z][a-z0-9]+)|([A-Z]+(?=[A-Z][a-z]))|((?<=\w)?[a-zA-Z0-9]+(?=\w)?)/',
+            $str->string,
+            $matches
+        );
+
+        $strings = array_map(
+            function (string $matchedString) {
+                return strtolower($matchedString);
+            },
+            $matches[0] ?? []
+        );
+
+        $str->string = implode('_', $strings);
 
         return $str;
     }
diff --git a/src/Symfony/Component/String/Tests/AbstractAsciiTestCase.php b/src/Symfony/Component/String/Tests/AbstractAsciiTestCase.php
index 14727da2394d2..1ac5db008a86b 100644
--- a/src/Symfony/Component/String/Tests/AbstractAsciiTestCase.php
+++ b/src/Symfony/Component/String/Tests/AbstractAsciiTestCase.php
@@ -1080,12 +1080,14 @@ public static function provideSnake()
             ['symfony_is_great', 'symfonyIsGREAT'],
             ['symfony_is_really_great', 'symfonyIsREALLYGreat'],
             ['symfony', 'SYMFONY'],
-            ['symfonyisgreat', 'SYMFONY IS GREAT'],
-            ['symfonyisgreat', 'SYMFONY_IS_GREAT'],
+            ['symfony_is_great', 'SYMFONY IS GREAT'],
+            ['symfony_is_great', 'SYMFONY_IS_GREAT'],
             ['symfony_is_great', 'symfony    is     great'],
-            ['symfonyisgreat', 'SYMFONY    IS     GREAT'],
-            ['symfonyisgreat', 'SYMFONY _ IS _ GREAT'],
-            ['symfony_isgreat', 'Symfony IS GREAT!'],
+            ['symfony_is_great', 'SYMFONY    IS     GREAT'],
+            ['symfony_is_great', 'SYMFONY _ IS _ GREAT'],
+            ['symfony_is_great', 'Symfony IS GREAT!'],
+            ['123_customer_with_special_name', '123-customer,with/special#name'],
+            ['this_value_should_be_false', 'This value should be false.'],
         ];
     }