diff --git a/src/Lexer.php b/src/Lexer.php
index 93c9e52820d..9556785e918 100644
--- a/src/Lexer.php
+++ b/src/Lexer.php
@@ -51,6 +51,10 @@ class Lexer
     private int $position;
     private array $positions;
     private int $currentVarBlockLine;
+    /**
+     * @var array<string>
+     */
+    private array $deprecations = [];
 
     public const STATE_DATA = 0;
     public const STATE_BLOCK = 1;
@@ -82,6 +86,8 @@ public function __construct(Environment $env, array $options = [])
 
     private function initialize()
     {
+        $this->deprecations = [];
+
         if ($this->isInitialized) {
             return;
         }
@@ -381,7 +387,7 @@ private function lexExpression(): void
         }
         // strings
         elseif (preg_match(self::REGEX_STRING, $this->code, $match, 0, $this->cursor)) {
-            $this->pushToken(/* Token::STRING_TYPE */ 7, stripcslashes(substr($match[0], 1, -1)));
+            $this->pushToken(/* Token::STRING_TYPE */ 7, $this->stripcslashes(substr($match[0], 1, -1), substr($match[0], 0, 1)));
             $this->moveCursor($match[0]);
         }
         // opening double quoted string
@@ -396,6 +402,64 @@ private function lexExpression(): void
         }
     }
 
+    private function stripcslashes(string $str, string $quoteType): string {
+        $result = '';
+        $length = strlen($str);
+        $specialChars = [
+            'f' => "\f",
+            'n' => "\n",
+            'r' => "\r",
+            't' => "\t",
+            'v' => "\v",
+        ];
+
+        for ($i = 0; $i < $length; $i++) {
+            if ($str[$i] === '\\' && $i + 1 < $length) {
+                $nextChar = $str[$i + 1];
+                if (isset($specialChars[$nextChar])) {
+                    $result .= $specialChars[$nextChar];
+                    $i++;
+                } elseif ($nextChar === '#') {
+                    $result .= "#";
+                    $i++;
+                } elseif ($nextChar === '\\') {
+                    if ($quoteType === "'" && (!($i + 2 < $length && isset($specialChars[$str[$i + 2]])))) {
+                        $this->deprecations[] = sprintf("Character %s at position %d does not require to be escaped.", $nextChar, $i + 2);
+                    }
+                    $result .= '\\';
+                    $i++;
+                } elseif ($nextChar === "'" || $nextChar === '"') {
+                    if ($nextChar !== $quoteType) {
+                        $this->deprecations[] = sprintf("Character %s at position %d does not require to be escaped.", $nextChar, $i + 2);
+                    }
+                    $result .= $nextChar;
+                    $i++;
+                } elseif ($nextChar === 'x' && $i + 2 < $length && ctype_xdigit($str[$i + 1]) && ctype_xdigit($str[$i + 2])) {
+                    $result .= chr(hexdec($str[$i + 1] . $str[$i + 2]));
+                    $i += 2;
+                } elseif (ctype_digit($nextChar) && $nextChar < '8') {
+                    $octal = $nextChar;
+                    for ($j = 1; $j <= 2; $j++) {
+                        if ($i + $j + 1 < $length && ctype_digit($str[$i + $j + 1]) && $str[$i + $j + 1] < '8') {
+                            $octal .= $str[$i + $j + 1];
+                            $i++;
+                        } else {
+                            break;
+                        }
+                    }
+                    $result .= chr(octdec($octal));
+                    $i++;
+                } else {
+                    $result .= '\\' . $nextChar;
+                    $i++;
+                }
+            } else {
+                $result .= $str[$i];
+            }
+        }
+        return $result;
+    }
+
     private function lexRawData(): void
     {
         if (!preg_match($this->regexes['lex_raw_data'], $this->code, $match, \PREG_OFFSET_CAPTURE, $this->cursor)) {
@@ -437,7 +501,7 @@ private function lexString(): void
             $this->moveCursor($match[0]);
             $this->pushState(self::STATE_INTERPOLATION);
         } elseif (preg_match(self::REGEX_DQ_STRING_PART, $this->code, $match, 0, $this->cursor) && '' !== $match[0]) {
-            $this->pushToken(/* Token::STRING_TYPE */ 7, stripcslashes($match[0]));
+            $this->pushToken(/* Token::STRING_TYPE */ 7, $this->stripcslashes($match[0], '"'));
             $this->moveCursor($match[0]);
         } elseif (preg_match(self::REGEX_DQ_STRING_DELIM, $this->code, $match, 0, $this->cursor)) {
             [$expect, $lineno] = array_pop($this->brackets);
@@ -530,4 +594,12 @@ private function popState(): void
 
         $this->state = array_pop($this->states);
     }
+
+    /**
+     * @return string[]
+     */
+    public function getDeprecations() : array
+    {
+        return $this->deprecations;
+    }
 }
diff --git a/tests/LexerTest.php b/tests/LexerTest.php
index 7926034ffa1..66600f31916 100644
--- a/tests/LexerTest.php
+++ b/tests/LexerTest.php
@@ -178,23 +178,97 @@ public function testBigNumbers()
         $this->assertEquals('922337203685477580700', $node->getValue());
     }
 
-    public function testStringWithEscapedDelimiter()
+    /**
+     * @dataProvider getStringWithEscapedDelimiter
+     */
+    public function testStringWithEscapedDelimiter(string $template, string $expected, array $expectedDeprecations = [])
     {
-        $tests = [
-            "{{ 'foo \' bar' }}" => 'foo \' bar',
-            '{{ "foo \" bar" }}' => 'foo " bar',
-        ];
-
         $lexer = new Lexer(new Environment(new ArrayLoader()));
-        foreach ($tests as $template => $expected) {
-            $stream = $lexer->tokenize(new Source($template, 'index'));
-            $stream->expect(Token::VAR_START_TYPE);
-            $stream->expect(Token::STRING_TYPE, $expected);
+        $stream = $lexer->tokenize(new Source($template, 'index'));
+        $stream->expect(Token::VAR_START_TYPE);
+        $stream->expect(Token::STRING_TYPE, $expected);
 
-            // add a dummy assertion here to satisfy PHPUnit, the only thing we want to test is that the code above
-            // can be executed without throwing any exceptions
-            $this->addToAssertionCount(1);
-        }
+        $this->assertSame($expectedDeprecations, $lexer->getDeprecations());
+    }
+
+    public function getStringWithEscapedDelimiter()
+    {
+        yield '{{ \'App\\\\Test\' }} => App\Test' => [
+            <<<'TWIG'
+            {{ 'App\\Test' }}
+            TWIG,
+            <<<'EOF'
+            App\Test
+            EOF,
+            [
+                'Character \ at position 5 does not require to be escaped.'
+            ]
+        ];
+        yield '{{ \'App\Test\' }} => App\Test' => [
+            <<<'TWIG'
+            {{ 'App\Test' }}
+            TWIG,
+            <<<'EOF'
+            App\Test
+            EOF,
+            []
+        ];
+        yield '{{ \'foo \\\' bar\' }} => foo \' bar' => [
+            <<<'TWIG'
+            {{ 'foo \' bar' }}
+            TWIG,
+            <<<'EOF'
+            foo ' bar
+            EOF,
+            [],
+        ];
+        yield '{{ "foo \\\' bar" }} => foo \' bar' => [
+            <<<'TWIG'
+            {{ "foo \' bar" }}
+            TWIG,
+            <<<'EOF'
+            foo ' bar
+            EOF,
+            [
+                "Character ' at position 6 does not require to be escaped.",
+            ],
+        ];
+        yield '{{ "foo \" bar" }} => foo " bar' => [
+            <<<'TWIG'
+            {{ "foo \" bar" }}
+            TWIG,
+            <<<'EOF'
+            foo " bar
+            EOF,
+            [],
+        ];
+        yield '{{ \'foo \" bar\' }} => foo " bar' => [
+            <<<'TWIG'
+            {{ 'foo \" bar' }}
+            TWIG,
+            <<<'EOF'
+            foo " bar
+            EOF,
+            [
+                'Character " at position 6 does not require to be escaped.',
+            ],
+        ];
+        yield '{{ \'\f\n\r\t\v\' }} => \f\n\r\t\v' => [
+            <<<'TWIG'
+            {{ '\f\n\r\t\v' }}
+            TWIG,
+            "\f\n\r\t\v",
+            [],
+        ];
+        yield '{{ \'\\\\f\\\\n\\\\r\\\\t\\\\v\' }} => \\f\\n\\r\\t\\v' => [
+            <<<'TWIG'
+            {{ '\\f\\n\\r\\t\\v' }}
+            TWIG,
+            <<<'EOF'
+            \f\n\r\t\v
+            EOF,
+            [],
+        ];
     }
 
     public function testStringWithInterpolation()