diff --git a/phpBB/adm/style/captcha_turnstile_acp.html b/phpBB/adm/style/captcha_turnstile_acp.html
index 446a0f436b..a187e1e41b 100644
--- a/phpBB/adm/style/captcha_turnstile_acp.html
+++ b/phpBB/adm/style/captcha_turnstile_acp.html
@@ -23,10 +23,24 @@
 			</dt>
 			<dd><input id="captcha_turnstile_secret" name="captcha_turnstile_secret" value="{{ CAPTCHA_TURNSTILE_SECRET }}" size="50" type="text" /></dd>
 		</dl>
+		<dl>
+			<dt>
+				<label>{{ lang('CAPTCHA_TURNSTILE_THEME') ~ lang('COLON') }}</label>
+				<br><span>{{ lang('CAPTCHA_TURNSTILE_THEME_EXPLAIN') }}</span>
+			</dt>
+			<dd>
+				{% for theme in CAPTCHA_TURNSTILE_THEMES %}
+				<label>
+					<input class="radio" name="captcha_turnstile_theme" type="radio" value="{{ theme }}"{{ theme == CAPTCHA_TURNSTILE_THEME ? ' checked' }}>
+					<span>{{ lang('CAPTCHA_TURNSTILE_THEME_' ~ theme|upper) }}</span>
+				</label>
+				{% endfor %}
+			</dd>
+		</dl>
 	</fieldset>
 	<fieldset>
 		<legend>{{ lang('PREVIEW') }}</legend>
-	{% if PREVIEW %}
+		{% if PREVIEW %}
 		<div class="successbox">
 			<h3>{{ lang('WARNING') }}</h3>
 			<p>{{ lang('CAPTCHA_PREVIEW_MSG') }}</p>
diff --git a/phpBB/adm/style/captcha_turnstile_acp_demo.html b/phpBB/adm/style/captcha_turnstile_acp_demo.html
index 348e96967a..757d0a4bcb 100644
--- a/phpBB/adm/style/captcha_turnstile_acp_demo.html
+++ b/phpBB/adm/style/captcha_turnstile_acp_demo.html
@@ -1,5 +1,5 @@
 <dl>
-	<dt><div id="captcha_turnstile"></div></dt>
+	<dt><div id="captcha_turnstile" data-language="{{ lang('TURNSTILE_LANG') }}"{% if TURNSTILE_THEME %} data-theme="{{ TURNSTILE_THEME }}"{% endif %}></div></dt>
 </dl>
 {% INCLUDEJS U_TURNSTILE_SCRIPT %}
 <script>
diff --git a/phpBB/install/schemas/schema_data.sql b/phpBB/install/schemas/schema_data.sql
index a160057fd2..b0e553960f 100644
--- a/phpBB/install/schemas/schema_data.sql
+++ b/phpBB/install/schemas/schema_data.sql
@@ -77,6 +77,9 @@ INSERT INTO phpbb_config (config_name, config_value) VALUES ('captcha_gd_wave',
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('captcha_gd_x_grid', '25');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('captcha_gd_y_grid', '25');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('captcha_plugin', 'core.captcha.plugins.incomplete');
+INSERT INTO phpbb_config (config_name, config_value) VALUES ('captcha_turnstile_sitekey', '');
+INSERT INTO phpbb_config (config_name, config_value) VALUES ('captcha_turnstile_secret', '');
+INSERT INTO phpbb_config (config_name, config_value) VALUES ('captcha_turnstile_theme', 'light');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('check_attachment_content', '1');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('check_dnsbl', '0');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('chg_passforce', '0');
diff --git a/phpBB/language/en/captcha_turnstile.php b/phpBB/language/en/captcha_turnstile.php
index 0fcf2c43d8..687ba4499d 100644
--- a/phpBB/language/en/captcha_turnstile.php
+++ b/phpBB/language/en/captcha_turnstile.php
@@ -40,9 +40,14 @@ $lang = array_merge($lang, [
 	'CAPTCHA_TURNSTILE'						=> 'Turnstile',
 	'CAPTCHA_TURNSTILE_INCORRECT'			=> 'The solution you provided was incorrect',
 	'CAPTCHA_TURNSTILE_NOSCRIPT'			=> 'Please enable JavaScript in your browser to load the challenge.',
+	'CAPTCHA_TURNSTILE_NOT_AVAILABLE'		=> 'In order to use Turnstile you must create a <a href="https://www.cloudflare.com/products/turnstile/">Cloudflare account</a>.',
 	'CAPTCHA_TURNSTILE_SECRET'				=> 'Secret key',
 	'CAPTCHA_TURNSTILE_SECRET_EXPLAIN'		=> 'Your Turnstile secret key. The secret key can be retrieved from your <a href="https://dash.cloudflare.com/?to=/:account/turnstile">Cloudflare dashboard</a>.',
 	'CAPTCHA_TURNSTILE_SITEKEY'				=> 'Sitekey',
 	'CAPTCHA_TURNSTILE_SITEKEY_EXPLAIN'		=> 'Your Turnstile sitekey. The sitekey can be retrieved from your <a href="https://dash.cloudflare.com/?to=/:account/turnstile">Cloudflare dashboard</a>.',
-	'CAPTCHA_TURNSTILE_NOT_AVAILABLE'		=> 'In order to use Turnstile you must create a <a href="https://www.cloudflare.com/products/turnstile/">Cloudflare account</a>.',
+	'CAPTCHA_TURNSTILE_THEME'				=> 'Widget theme',
+	'CAPTCHA_TURNSTILE_THEME_EXPLAIN'		=> 'The theme of the CAPTCHA widget. By default, <samp>light</samp> will be used. Other possibilities are <samp>dark</samp> and <samp>auto</samp>, which respects the user’s preference.',
+	'CAPTCHA_TURNSTILE_THEME_AUTO'			=> 'Auto',
+	'CAPTCHA_TURNSTILE_THEME_DARK'			=> 'Dark',
+	'CAPTCHA_TURNSTILE_THEME_LIGHT'			=> 'Light',
 ]);
diff --git a/phpBB/language/en/composer.json b/phpBB/language/en/composer.json
index 7402e5efa5..cd6bcdb581 100644
--- a/phpBB/language/en/composer.json
+++ b/phpBB/language/en/composer.json
@@ -26,6 +26,7 @@
 		"direction": "ltr",
 		"user-lang": "en-gb",
 		"plural-rule": 1,
-		"recaptcha-lang": "en-GB"
+		"recaptcha-lang": "en-GB",
+		"turnstile-lang": "en"
 	}
 }
diff --git a/phpBB/phpbb/captcha/plugins/turnstile.php b/phpBB/phpbb/captcha/plugins/turnstile.php
index 0e56a340e4..b3152b2a23 100644
--- a/phpBB/phpbb/captcha/plugins/turnstile.php
+++ b/phpBB/phpbb/captcha/plugins/turnstile.php
@@ -53,6 +53,13 @@ class turnstile extends base
 	/** @var string Service name */
 	protected string $service_name = '';
 
+	/** @var array|string[] Supported themes for Turnstile CAPTCHA */
+	protected static array $supported_themes = [
+		'light',
+		'dark',
+		'auto'
+	];
+
 	/**
 	 * Constructor for turnstile captcha plugin
 	 *
@@ -205,6 +212,7 @@ class turnstile extends base
 		$this->template->assign_vars([
 			'S_TURNSTILE_AVAILABLE'	=> $this->is_available(),
 			'TURNSTILE_SITEKEY'		=> $this->config->offsetGet('captcha_turnstile_sitekey'),
+			'TURNSTILE_THEME'		=> $this->config->offsetGet('captcha_turnstile_theme'),
 			'U_TURNSTILE_SCRIPT'	=> self::SCRIPT_URL,
 		]);
 
@@ -214,6 +222,7 @@ class turnstile extends base
 	public function get_demo_template(): string
 	{
 		$this->template->assign_vars([
+			'TURNSTILE_THEME'		=> $this->config->offsetGet('captcha_turnstile_theme'),
 			'U_TURNSTILE_SCRIPT'	=> self::SCRIPT_URL,
 		]);
 
@@ -254,6 +263,12 @@ class turnstile extends base
 				}
 			}
 
+			$captcha_theme = $this->request->variable('captcha_turnstile_theme', self::$supported_themes[0]);
+			if (in_array($captcha_theme, self::$supported_themes))
+			{
+				$this->config->set('captcha_turnstile_theme', $captcha_theme);
+			}
+
 			$this->log->add('admin', $this->user->data['user_id'], $this->user->ip, 'LOG_CONFIG_VISUAL');
 			trigger_error($this->language->lang('CONFIG_UPDATED') . adm_back_link($module->u_action));
 		}
@@ -270,9 +285,11 @@ class turnstile extends base
 			}
 
 			$this->template->assign_vars(array(
-				'CAPTCHA_PREVIEW'		=> $this->get_demo_template(),
-				'CAPTCHA_NAME'			=> $this->service_name,
-				'U_ACTION'				=> $module->u_action,
+				'CAPTCHA_PREVIEW'			=> $this->get_demo_template(),
+				'CAPTCHA_NAME'				=> $this->service_name,
+				'CAPTCHA_TURNSTILE_THEME'	=> $this->config->offsetGet('captcha_turnstile_theme'),
+				'CAPTCHA_TURNSTILE_THEMES'	=> self::$supported_themes,
+				'U_ACTION'					=> $module->u_action,
 			));
 		}
 	}
diff --git a/phpBB/phpbb/db/migration/data/v400/turnstile_captcha.php b/phpBB/phpbb/db/migration/data/v400/turnstile_captcha.php
index 06111c9306..77e921c090 100644
--- a/phpBB/phpbb/db/migration/data/v400/turnstile_captcha.php
+++ b/phpBB/phpbb/db/migration/data/v400/turnstile_captcha.php
@@ -20,7 +20,8 @@ class turnstile_captcha extends migration
 	public function effectively_installed(): bool
 	{
 		return $this->config->offsetExists('captcha_turnstile_sitekey')
-			&& $this->config->offsetExists('captcha_turnstile_secret');
+			&& $this->config->offsetExists('captcha_turnstile_secret')
+			&& $this->config->offsetExists('captcha_turnstile_theme');
 	}
 
 	public static function depends_on(): array
@@ -35,6 +36,7 @@ class turnstile_captcha extends migration
 		return [
 			['config.add', ['captcha_turnstile_sitekey', '']],
 			['config.add', ['captcha_turnstile_secret', '']],
+			['config.add', ['captcha_turnstile_theme', 'light']],
 		];
 	}
 
@@ -43,6 +45,7 @@ class turnstile_captcha extends migration
 		return [
 			['config.remove', ['captcha_turnstile_sitekey']],
 			['config.remove', ['captcha_turnstile_secret']],
+			['config.remove', ['captcha_turnstile_theme']],
 		];
 	}
 }
diff --git a/phpBB/phpbb/language/language.php b/phpBB/phpbb/language/language.php
index dee8b58486..1c51049de5 100644
--- a/phpBB/phpbb/language/language.php
+++ b/phpBB/phpbb/language/language.php
@@ -403,6 +403,7 @@ class language
 		$this->lang['USER_LANG'] = $lang_values['user_lang'] ?? 'en-gb';
 		$this->lang['PLURAL_RULE'] = $lang_values['plural_rule'] ?? 1;
 		$this->lang['RECAPTCHA_LANG'] = $lang_values['recaptcha_lang'] ?? 'en-GB';
+		$this->lang['TURNSTILE_LANG'] = $lang_values['turnstile_lang'] ?? 'auto'; // default to auto mode
 	}
 
 	/**
diff --git a/phpBB/phpbb/language/language_file_helper.php b/phpBB/phpbb/language/language_file_helper.php
index 995c7b4712..83244d674f 100644
--- a/phpBB/phpbb/language/language_file_helper.php
+++ b/phpBB/phpbb/language/language_file_helper.php
@@ -110,16 +110,17 @@ class language_file_helper
 		}
 
 		return [
-			'iso'			=> $data['extra']['language-iso'],
-			'name'			=> $data['extra']['english-name'],
-			'local_name'	=> $data['extra']['local-name'],
-			'author'		=> implode(', ', $authors),
-			'version'		=> $data['version'],
-			'phpbb_version'	=> $data['extra']['phpbb-version'],
-			'direction'		=> $data['extra']['direction'],
-			'user_lang'		=> $data['extra']['user-lang'],
-			'plural_rule'	=> $data['extra']['plural-rule'],
-			'recaptcha_lang'=> $data['extra']['recaptcha-lang'],
+			'iso'				=> $data['extra']['language-iso'],
+			'name'				=> $data['extra']['english-name'],
+			'local_name'		=> $data['extra']['local-name'],
+			'author'			=> implode(', ', $authors),
+			'version'			=> $data['version'],
+			'phpbb_version'		=> $data['extra']['phpbb-version'],
+			'direction'			=> $data['extra']['direction'],
+			'user_lang'			=> $data['extra']['user-lang'],
+			'plural_rule'		=> $data['extra']['plural-rule'],
+			'recaptcha_lang'	=> $data['extra']['recaptcha-lang'],
+			'turnstile_lang'	=> $data['extra']['turnstile-lang'] ?? '',
 		];
 	}
 }
diff --git a/phpBB/styles/prosilver/template/captcha_turnstile.html b/phpBB/styles/prosilver/template/captcha_turnstile.html
index f13d1fa882..f20d53e539 100644
--- a/phpBB/styles/prosilver/template/captcha_turnstile.html
+++ b/phpBB/styles/prosilver/template/captcha_turnstile.html
@@ -6,7 +6,7 @@
 	<script src="{{ U_TURNSTILE_SCRIPT }}" async defer></script>
 
 	{# The cf-turnstile class is used in JavaScript #}
-	<div class="cf-turnstile" data-sitekey="{{ TURNSTILE_SITEKEY }}"></div>
+	<div class="cf-turnstile" data-sitekey="{{ TURNSTILE_SITEKEY }}"{% if TURNSTILE_THEME %} data-theme="{{ TURNSTILE_THEME }}"{% endif %}></div>
 {% else %}
 	{{ lang('CAPTCHA_TURNSTILE_NOT_AVAILABLE') }}
 {% endif %}