diff --git a/src/Env/Filters.php b/src/Env/Filters.php
index d5d276e..a087eb4 100644
--- a/src/Env/Filters.php
+++ b/src/Env/Filters.php
@@ -33,6 +33,7 @@ final class Filters
     public const FILTER_INT_OR_BOOL = 'int|bool';
     public const FILTER_STRING_OR_BOOL = 'string|bool';
     public const FILTER_STRING = 'string';
+    public const FILTER_RAW_STRING = 'raw-string';
     public const FILTER_OCTAL_MOD = 'mod';
     public const FILTER_TABLE_PREFIX = 'table-prefix';
 
@@ -87,6 +88,8 @@ private function applyFilter(string $mode, $value)
                 return $this->filterFloat($value);
             case self::FILTER_STRING:
                 return $this->filterString($value);
+            case self::FILTER_RAW_STRING:
+                return $this->filterRawString($value);
             case self::FILTER_INT_OR_BOOL:
                 return $this->filterIntOrBool($value);
             case self::FILTER_STRING_OR_BOOL:
@@ -157,6 +160,19 @@ private function filterString($value): string
         return htmlspecialchars(strip_tags((string)$value), ENT_QUOTES, 'UTF-8', false);
     }
 
+    /**
+     * @param mixed $value
+     * @return string
+     */
+    private function filterRawString($value): string
+    {
+        if (!is_scalar($value)) {
+            throw new \Exception('Invalid scalar.');
+        }
+
+        return addslashes((string)$value);
+    }
+
     /**
      * @param mixed $value
      * @return bool|int
diff --git a/src/Env/WordPressEnvBridge.php b/src/Env/WordPressEnvBridge.php
index a670f51..5576d76 100644
--- a/src/Env/WordPressEnvBridge.php
+++ b/src/Env/WordPressEnvBridge.php
@@ -25,8 +25,8 @@ class WordPressEnvBridge
         'ALLOW_UNFILTERED_UPLOADS' => Filters::FILTER_BOOL,
         'ALTERNATE_WP_CRON' => Filters::FILTER_BOOL,
         'AUTH_COOKIE' => Filters::FILTER_STRING,
-        'AUTH_KEY' => Filters::FILTER_STRING,
-        'AUTH_SALT' => Filters::FILTER_STRING,
+        'AUTH_KEY' => Filters::FILTER_RAW_STRING,
+        'AUTH_SALT' => Filters::FILTER_RAW_STRING,
         'AUTOMATIC_UPDATER_DISABLED' => Filters::FILTER_BOOL,
         'AUTOSAVE_INTERVAL' => Filters::FILTER_INT,
 
@@ -50,7 +50,7 @@ class WordPressEnvBridge
         'DB_COLLATE' => Filters::FILTER_STRING,
         'DB_HOST' => Filters::FILTER_STRING,
         'DB_NAME' => Filters::FILTER_STRING,
-        'DB_PASSWORD' => Filters::FILTER_STRING,
+        'DB_PASSWORD' => Filters::FILTER_RAW_STRING,
         'DB_USER' => Filters::FILTER_STRING,
         'DIEONDBERROR' => Filters::FILTER_BOOL,
         'DISABLE_WP_CRON' => Filters::FILTER_BOOL,
@@ -80,7 +80,7 @@ class WordPressEnvBridge
         'FTP_FORCE' => Filters::FILTER_BOOL,
         'FTP_HOST' => Filters::FILTER_STRING,
         'FTP_LANG_DIR' => Filters::FILTER_STRING,
-        'FTP_PASS' => Filters::FILTER_STRING,
+        'FTP_PASS' => Filters::FILTER_RAW_STRING,
         'FTP_PLUGIN_DIR' => Filters::FILTER_STRING,
         'FTP_PRIKEY' => Filters::FILTER_STRING,
         'FTP_PUBKEY' => Filters::FILTER_STRING,
@@ -97,8 +97,8 @@ class WordPressEnvBridge
 
         'LANGDIR' => Filters::FILTER_STRING,
         'LOGGED_IN_COOKIE' => Filters::FILTER_STRING,
-        'LOGGED_IN_KEY' => Filters::FILTER_STRING,
-        'LOGGED_IN_SALT' => Filters::FILTER_STRING,
+        'LOGGED_IN_KEY' => Filters::FILTER_RAW_STRING,
+        'LOGGED_IN_SALT' => Filters::FILTER_RAW_STRING,
 
         'MEDIA_TRASH' => Filters::FILTER_BOOL,
         'MULTISITE' => Filters::FILTER_BOOL,
@@ -108,8 +108,8 @@ class WordPressEnvBridge
         'MYSQL_NEW_LINK' => Filters::FILTER_BOOL,
 
         'NOBLOGREDIRECT' => Filters::FILTER_STRING,
-        'NONCE_KEY' => Filters::FILTER_STRING,
-        'NONCE_SALT' => Filters::FILTER_STRING,
+        'NONCE_KEY' => Filters::FILTER_RAW_STRING,
+        'NONCE_SALT' => Filters::FILTER_RAW_STRING,
         'NO_HEADER_TEXT' => Filters::FILTER_STRING,
 
         'PASS_COOKIE' => Filters::FILTER_STRING,
@@ -129,11 +129,11 @@ class WordPressEnvBridge
 
         'SAVEQUERIES' => Filters::FILTER_BOOL,
         'SCRIPT_DEBUG' => Filters::FILTER_BOOL,
-        'SECRET_KEY' => Filters::FILTER_STRING,
-        'SECRET_SALT' => Filters::FILTER_STRING,
+        'SECRET_KEY' => Filters::FILTER_RAW_STRING,
+        'SECRET_SALT' => Filters::FILTER_RAW_STRING,
         'SECURE_AUTH_COOKIE' => Filters::FILTER_STRING,
-        'SECURE_AUTH_KEY' => Filters::FILTER_STRING,
-        'SECURE_AUTH_SALT' => Filters::FILTER_STRING,
+        'SECURE_AUTH_KEY' => Filters::FILTER_RAW_STRING,
+        'SECURE_AUTH_SALT' => Filters::FILTER_RAW_STRING,
         'SHORTINIT' => Filters::FILTER_BOOL,
         'SITECOOKIEPATH' => Filters::FILTER_STRING,
         'SITE_ID_CURRENT_SITE' => Filters::FILTER_INT,
@@ -177,7 +177,7 @@ class WordPressEnvBridge
         'WP_POST_REVISIONS' => Filters::FILTER_INT_OR_BOOL,
         'WP_PROXY_BYPASS_HOSTS' => Filters::FILTER_STRING,
         'WP_PROXY_HOST' => Filters::FILTER_STRING,
-        'WP_PROXY_PASSWORD' => Filters::FILTER_STRING,
+        'WP_PROXY_PASSWORD' => Filters::FILTER_RAW_STRING,
         'WP_PROXY_PORT' => Filters::FILTER_INT,
         'WP_PROXY_USERNAME' => Filters::FILTER_STRING,
         'WP_SITEURL' => Filters::FILTER_STRING,
diff --git a/tests/fixtures/example.env b/tests/fixtures/example.env
index 33351bd..10bfa22 100644
--- a/tests/fixtures/example.env
+++ b/tests/fixtures/example.env
@@ -1,6 +1,6 @@
 DB_HOST=localhost
 DB_NAME=wp
-DB_PASSWORD="my secret!"
+DB_PASSWORD="foo&bar!baz<qux"
 DB_TABLE_PREFIX=xxx_
 DB_USER="${DB_NAME}_user"
 
diff --git a/tests/integration/Env/WordPressEnvBridgeTest.php b/tests/integration/Env/WordPressEnvBridgeTest.php
index 28ac3ee..2b203bb 100644
--- a/tests/integration/Env/WordPressEnvBridgeTest.php
+++ b/tests/integration/Env/WordPressEnvBridgeTest.php
@@ -46,7 +46,7 @@ public function testLoadFile(): void
 
         static::assertSame('localhost', $bridge->read('DB_HOST'));
         static::assertSame('wp', $bridge->read('DB_NAME'));
-        static::assertSame('my secret!', $bridge->read('DB_PASSWORD'));
+        static::assertSame('foo&bar!baz<qux', $bridge->read('DB_PASSWORD'));
         static::assertSame('xxx_', $bridge->read('DB_TABLE_PREFIX'));
         static::assertSame('wp_user', $bridge->read('DB_USER'));
         static::assertSame('', $bridge->read('COOKIE_DOMAIN'));
diff --git a/tests/unit/Env/FiltersTest.php b/tests/unit/Env/FiltersTest.php
index e94247d..c8e9452 100644
--- a/tests/unit/Env/FiltersTest.php
+++ b/tests/unit/Env/FiltersTest.php
@@ -84,6 +84,19 @@ public static function filterDataProvider(): array
             [Filters::FILTER_STRING, [], null],
             [Filters::FILTER_STRING, '', ''],
             [Filters::FILTER_STRING, "", ''],
+            [Filters::FILTER_RAW_STRING, 1, '1'],
+            [Filters::FILTER_RAW_STRING, 123.456, '123.456'],
+            [Filters::FILTER_RAW_STRING, 0, '0'],
+            [Filters::FILTER_RAW_STRING, new \ArrayObject(), null],
+            [Filters::FILTER_RAW_STRING, false, ''],
+            [Filters::FILTER_RAW_STRING, true, '1'],
+            [Filters::FILTER_RAW_STRING, [], null],
+            [Filters::FILTER_RAW_STRING, '', ''],
+            [Filters::FILTER_RAW_STRING, "", ''],
+            [Filters::FILTER_RAW_STRING, 'hello!', 'hello!'],
+            [Filters::FILTER_RAW_STRING, 'foo&bar', 'foo&bar'],
+            [Filters::FILTER_RAW_STRING, 'foo<bar', 'foo<bar'],
+            [Filters::FILTER_RAW_STRING, "foo'", "foo\'"],
             [Filters::FILTER_INT_OR_BOOL, 1, 1],
             [Filters::FILTER_INT_OR_BOOL, '1', 1],
             [Filters::FILTER_INT_OR_BOOL, 123.123, 123],