diff --git a/.github/workflows/testing.yaml b/.github/workflows/testing.yaml
index 5e8004be..b726e52a 100644
--- a/.github/workflows/testing.yaml
+++ b/.github/workflows/testing.yaml
@@ -19,7 +19,7 @@ jobs:
                 options: --health-cmd="mysqladmin ping" --health-interval=10s --health-timeout=5s --health-retries=3
         strategy:
             matrix:
-                php: ['8.1', '8.2']
+                php: ['8.1', '8.2', '8.3']
 
         name: Integration (${{ matrix.php }})
         steps:
@@ -92,7 +92,7 @@ jobs:
                     TEST_WITH_BUNDLES: 1
 
             -   name: Upload code coverage
-                if: matrix.php == '8.1'
+                if: matrix.php == '8.2'
                 uses: codecov/codecov-action@v3
                 with:
                     token: ${{ secrets.CODECOV_TOKEN }}
diff --git a/README.md b/README.md
index 59a2b03a..b96dab2d 100644
--- a/README.md
+++ b/README.md
@@ -38,11 +38,13 @@ Do **NOT** use Version 1, it won't get any more updates!
 
 ### Requirements
 
-- PHP 8.1 minimum
+- PHP 8.1.3 minimum
 - MariaDB or MySQL
 - A webserver and subdomain (subdirectory is not supported)
 - PHP extensions: `gd`, `intl`, `json`, `mbstring`, `pdo`, `tokenizer`, `xml`, `xsl`, `zip`
 
+Support for PHP 8.2 and 8.3.
+
 ## Installation
 
 - [Recommended setup](https://www.kimai.org/documentation/installation.html#recommended-setup) — with Git and Composer
diff --git a/composer.json b/composer.json
index f3c804b7..ac5fc0a2 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
         }
     ],
     "require": {
-        "php": "8.1.*||8.2.*",
+        "php": "8.1.*||8.2.*||8.3.*",
         "ext-gd": "*",
         "ext-intl": "*",
         "ext-json": "*",
diff --git a/composer.lock b/composer.lock
index 901cb412..340304e2 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "0a45772bb5617dc0e021b6b24120468e",
+    "content-hash": "3573d958deb04f566945c3dbd7414fa3",
     "packages": [
         {
             "name": "azuyalabs/yasumi",
@@ -5488,16 +5488,16 @@
         },
         {
             "name": "symfony/dependency-injection",
-            "version": "v6.3.8",
+            "version": "v6.3.10",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/dependency-injection.git",
-                "reference": "1f30f545c4151f611148fc19e28d54d39e0a00bc"
+                "reference": "51383a1d9d7e93d5c3c76ddc32672de1b3e82c77"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/dependency-injection/zipball/1f30f545c4151f611148fc19e28d54d39e0a00bc",
-                "reference": "1f30f545c4151f611148fc19e28d54d39e0a00bc",
+                "url": "https://api.github.com/repos/symfony/dependency-injection/zipball/51383a1d9d7e93d5c3c76ddc32672de1b3e82c77",
+                "reference": "51383a1d9d7e93d5c3c76ddc32672de1b3e82c77",
                 "shasum": ""
             },
             "require": {
@@ -5549,7 +5549,7 @@
             "description": "Allows you to standardize and centralize the way objects are constructed in your application",
             "homepage": "https://symfony.com",
             "support": {
-                "source": "https://github.com/symfony/dependency-injection/tree/v6.3.8"
+                "source": "https://github.com/symfony/dependency-injection/tree/v6.3.10"
             },
             "funding": [
                 {
@@ -5565,7 +5565,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2023-10-31T08:07:48+00:00"
+            "time": "2023-12-01T14:25:58+00:00"
         },
         {
             "name": "symfony/deprecation-contracts",
@@ -6306,16 +6306,16 @@
         },
         {
             "name": "symfony/form",
-            "version": "v6.3.8",
+            "version": "v6.3.10",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/form.git",
-                "reference": "b7a8098163cce87c0b6ce05d0f361dc12d5a2788"
+                "reference": "5afc7334b9d60dd0799612faf3d103b25bc60ae4"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/form/zipball/b7a8098163cce87c0b6ce05d0f361dc12d5a2788",
-                "reference": "b7a8098163cce87c0b6ce05d0f361dc12d5a2788",
+                "url": "https://api.github.com/repos/symfony/form/zipball/5afc7334b9d60dd0799612faf3d103b25bc60ae4",
+                "reference": "5afc7334b9d60dd0799612faf3d103b25bc60ae4",
                 "shasum": ""
             },
             "require": {
@@ -6383,7 +6383,7 @@
             "description": "Allows to easily create, process and reuse HTML forms",
             "homepage": "https://symfony.com",
             "support": {
-                "source": "https://github.com/symfony/form/tree/v6.3.8"
+                "source": "https://github.com/symfony/form/tree/v6.3.10"
             },
             "funding": [
                 {
@@ -6399,7 +6399,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2023-11-06T10:58:05+00:00"
+            "time": "2023-11-30T11:08:22+00:00"
         },
         {
             "name": "symfony/framework-bundle",
@@ -6794,16 +6794,16 @@
         },
         {
             "name": "symfony/http-kernel",
-            "version": "v6.3.9",
+            "version": "v6.3.10",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/http-kernel.git",
-                "reference": "d63fe6b1e3ad2f037f6f000a6fc867fa8934f35c"
+                "reference": "8d8e7aa60593fd0a2e3c1cea08cc687314841b61"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/http-kernel/zipball/d63fe6b1e3ad2f037f6f000a6fc867fa8934f35c",
-                "reference": "d63fe6b1e3ad2f037f6f000a6fc867fa8934f35c",
+                "url": "https://api.github.com/repos/symfony/http-kernel/zipball/8d8e7aa60593fd0a2e3c1cea08cc687314841b61",
+                "reference": "8d8e7aa60593fd0a2e3c1cea08cc687314841b61",
                 "shasum": ""
             },
             "require": {
@@ -6887,7 +6887,7 @@
             "description": "Provides a structured process for converting a Request into a Response",
             "homepage": "https://symfony.com",
             "support": {
-                "source": "https://github.com/symfony/http-kernel/tree/v6.3.9"
+                "source": "https://github.com/symfony/http-kernel/tree/v6.3.10"
             },
             "funding": [
                 {
@@ -6903,7 +6903,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2023-11-29T10:24:27+00:00"
+            "time": "2023-12-01T16:57:27+00:00"
         },
         {
             "name": "symfony/intl",
@@ -8100,16 +8100,16 @@
         },
         {
             "name": "symfony/routing",
-            "version": "v6.3.5",
+            "version": "v6.3.10",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/routing.git",
-                "reference": "82616e59acd3e3d9c916bba798326cb7796d7d31"
+                "reference": "cb7404232d49dd11cc971b832fcbd49e7c22b049"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/routing/zipball/82616e59acd3e3d9c916bba798326cb7796d7d31",
-                "reference": "82616e59acd3e3d9c916bba798326cb7796d7d31",
+                "url": "https://api.github.com/repos/symfony/routing/zipball/cb7404232d49dd11cc971b832fcbd49e7c22b049",
+                "reference": "cb7404232d49dd11cc971b832fcbd49e7c22b049",
                 "shasum": ""
             },
             "require": {
@@ -8163,7 +8163,7 @@
                 "url"
             ],
             "support": {
-                "source": "https://github.com/symfony/routing/tree/v6.3.5"
+                "source": "https://github.com/symfony/routing/tree/v6.3.10"
             },
             "funding": [
                 {
@@ -8179,7 +8179,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2023-09-20T16:05:51+00:00"
+            "time": "2023-12-01T14:25:58+00:00"
         },
         {
             "name": "symfony/runtime",
@@ -8614,16 +8614,16 @@
         },
         {
             "name": "symfony/serializer",
-            "version": "v6.3.9",
+            "version": "v6.3.10",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/serializer.git",
-                "reference": "87faafcc88ace143b30fdc34b240d9a3603bc95e"
+                "reference": "6eee0fd95f5caa1e77cab29552620ebf8e5b1a5f"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/serializer/zipball/87faafcc88ace143b30fdc34b240d9a3603bc95e",
-                "reference": "87faafcc88ace143b30fdc34b240d9a3603bc95e",
+                "url": "https://api.github.com/repos/symfony/serializer/zipball/6eee0fd95f5caa1e77cab29552620ebf8e5b1a5f",
+                "reference": "6eee0fd95f5caa1e77cab29552620ebf8e5b1a5f",
                 "shasum": ""
             },
             "require": {
@@ -8688,7 +8688,7 @@
             "description": "Handles serializing and deserializing data structures, including object graphs, into array structures or other formats like XML and JSON.",
             "homepage": "https://symfony.com",
             "support": {
-                "source": "https://github.com/symfony/serializer/tree/v6.3.9"
+                "source": "https://github.com/symfony/serializer/tree/v6.3.10"
             },
             "funding": [
                 {
@@ -8704,7 +8704,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2023-11-29T10:00:30+00:00"
+            "time": "2023-12-01T14:25:58+00:00"
         },
         {
             "name": "symfony/service-contracts",
@@ -9484,16 +9484,16 @@
         },
         {
             "name": "symfony/var-exporter",
-            "version": "v6.3.9",
+            "version": "v6.3.10",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/var-exporter.git",
-                "reference": "a00fd2d47af5c95e95e8e371a74be2e79b95dfae"
+                "reference": "7bfcf232a9c7e4acad00e96774e340eb86d10bf0"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/var-exporter/zipball/a00fd2d47af5c95e95e8e371a74be2e79b95dfae",
-                "reference": "a00fd2d47af5c95e95e8e371a74be2e79b95dfae",
+                "url": "https://api.github.com/repos/symfony/var-exporter/zipball/7bfcf232a9c7e4acad00e96774e340eb86d10bf0",
+                "reference": "7bfcf232a9c7e4acad00e96774e340eb86d10bf0",
                 "shasum": ""
             },
             "require": {
@@ -9538,7 +9538,7 @@
                 "serialize"
             ],
             "support": {
-                "source": "https://github.com/symfony/var-exporter/tree/v6.3.9"
+                "source": "https://github.com/symfony/var-exporter/tree/v6.3.10"
             },
             "funding": [
                 {
@@ -9554,7 +9554,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2023-11-28T20:34:48+00:00"
+            "time": "2023-11-29T16:00:50+00:00"
         },
         {
             "name": "symfony/webpack-encore-bundle",
@@ -13068,16 +13068,16 @@
         },
         {
             "name": "symfony/phpunit-bridge",
-            "version": "v6.4.0",
+            "version": "v6.4.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/phpunit-bridge.git",
-                "reference": "36bc5bc71fff1f6ca9c7c7fe1e7e23f4c1ca2aa3"
+                "reference": "cca5373a41d45edbeaf38b7b67f376da2205ff95"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/phpunit-bridge/zipball/36bc5bc71fff1f6ca9c7c7fe1e7e23f4c1ca2aa3",
-                "reference": "36bc5bc71fff1f6ca9c7c7fe1e7e23f4c1ca2aa3",
+                "url": "https://api.github.com/repos/symfony/phpunit-bridge/zipball/cca5373a41d45edbeaf38b7b67f376da2205ff95",
+                "reference": "cca5373a41d45edbeaf38b7b67f376da2205ff95",
                 "shasum": ""
             },
             "require": {
@@ -13129,7 +13129,7 @@
             "description": "Provides utilities for PHPUnit, especially user deprecation notices management",
             "homepage": "https://symfony.com",
             "support": {
-                "source": "https://github.com/symfony/phpunit-bridge/tree/v6.4.0"
+                "source": "https://github.com/symfony/phpunit-bridge/tree/v6.4.1"
             },
             "funding": [
                 {
@@ -13145,7 +13145,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2023-10-31T08:18:17+00:00"
+            "time": "2023-12-01T09:25:07+00:00"
         },
         {
             "name": "symfony/process",
@@ -13346,7 +13346,7 @@
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
-        "php": "8.1.*||8.2.*",
+        "php": "8.1.*||8.2.*||8.3.*",
         "ext-gd": "*",
         "ext-intl": "*",
         "ext-json": "*",
diff --git a/src/Export/Base/XlsxRenderer.php b/src/Export/Base/XlsxRenderer.php
index 10a749cf..41c25f75 100644
--- a/src/Export/Base/XlsxRenderer.php
+++ b/src/Export/Base/XlsxRenderer.php
@@ -66,12 +66,11 @@ class XlsxRenderer extends AbstractSpreadsheetRenderer
         // Freeze first row and date & time columns for easier navigation
         $sheet->freezePane('D2');
 
-        /** @var string $column */
-        foreach (range('A', $highestColumn) as $column) {
+        foreach ($sheet->getColumnIterator() as $columnName => $column) {
             // We default to a reasonable auto-width decided by the client,
             // sadly ->getDefaultColumnDimension() is not supported so it needs
             // to be specific about what column should be auto sized.
-            $col = $sheet->getColumnDimension($column);
+            $col = $sheet->getColumnDimension($columnName);
 
             // If no other width is specified (which defaults to -1)
             if ((int) $col->getWidth() === -1) {
diff --git a/src/Export/Spreadsheet/Writer/XlsxWriter.php b/src/Export/Spreadsheet/Writer/XlsxWriter.php
index 8ed18a4a..807327d0 100644
--- a/src/Export/Spreadsheet/Writer/XlsxWriter.php
+++ b/src/Export/Spreadsheet/Writer/XlsxWriter.php
@@ -59,12 +59,11 @@ final class XlsxWriter implements WriterInterface
             $sheet->freezePane($options['freeze']);
         }
 
-        /** @var string $column */
-        foreach (range('A', $highestColumn) as $column) {
+        foreach ($sheet->getColumnIterator() as $columnName => $column) {
             // We default to a reasonable auto-width decided by the client,
             // sadly ->getDefaultColumnDimension() is not supported so it needs
             // to be specific about what column should be auto sized.
-            $col = $sheet->getColumnDimension($column);
+            $col = $sheet->getColumnDimension($columnName);
 
             // If no other width is specified (which defaults to -1)
             if ((int) $col->getWidth() === -1) {