diff --git a/lib/AppInfo/Application.php b/lib/AppInfo/Application.php
index c34ddfe6..708d1b35 100644
--- a/lib/AppInfo/Application.php
+++ b/lib/AppInfo/Application.php
@@ -46,6 +46,8 @@ class Application extends App implements IBootstrap {
 	public const DEFAULT_QUOTA_PERIOD = 30;
 	public const MAX_QUOTA_PERIOD_DAYS = 3650;
 	public const MAX_QUOTA_PERIOD_MONTHS = 120;
+	public const DEFAULT_SUMMARY_SYSTEM_PROMPT = 'You are a helpful assistant that summarizes text in the same language as the text. '
+		. 'You should only return the summary without any additional information.';
 	public const DEFAULT_QUOTA_CONFIG = ['length' => self::DEFAULT_QUOTA_PERIOD, 'unit' => 'day', 'day' => 1];
 
 	public const DEFAULT_OPENAI_TEXT_GENERATION_TIME = 10; // seconds
diff --git a/lib/Service/OpenAiSettingsService.php b/lib/Service/OpenAiSettingsService.php
index 8e48a555..33e17570 100644
--- a/lib/Service/OpenAiSettingsService.php
+++ b/lib/Service/OpenAiSettingsService.php
@@ -27,6 +27,7 @@ class OpenAiSettingsService {
 	private const ADMIN_CONFIG_TYPES = [
 		'quota_period' => 'array',
 		'usage_storage_time' => 'integer',
+		'summary_system_prompt' => 'string',
 	];
 
 	private const USER_CONFIG_TYPES = [
@@ -135,6 +136,19 @@ public function getUsageStorageTime(): int {
 		return $this->appConfig->getValueInt(Application::APP_ID, 'usage_storage_time', Application::DEFAULT_QUOTA_PERIOD, lazy: true);
 	}
 
+	/**
+	 * System prompt for the summary provider. Empty falls back to the default unless $raw is true.
+	 */
+	public function getSummarySystemPrompt(bool $raw = false): string {
+		$default = $raw ? '' : Application::DEFAULT_SUMMARY_SYSTEM_PROMPT;
+		return $this->appConfig->getValueString(
+			Application::APP_ID,
+			'summary_system_prompt',
+			$default,
+			lazy: true
+		) ?: $default;
+	}
+
 	/**
 	 * @param string|null $userId
 	 * @return string
@@ -146,12 +160,13 @@ public function getUserSTTLanguage(?string $userId): string {
 	/**
 	 * Get the instance-wide admin config for the settings page
 	 *
-	 * @return array{quota_period: array, usage_storage_time: int}
+	 * @return array{quota_period: array, usage_storage_time: int, summary_system_prompt: string}
 	 */
 	public function getAdminConfig(): array {
 		return [
 			'quota_period' => $this->getQuotaPeriod(),
 			'usage_storage_time' => $this->getUsageStorageTime(),
+			'summary_system_prompt' => $this->getSummarySystemPrompt(true),
 		];
 	}
 
@@ -218,6 +233,15 @@ public function setUsageStorageTime(int $usageStorageTime): void {
 		$this->appConfig->setValueInt(Application::APP_ID, 'usage_storage_time', $usageStorageTime, lazy: true);
 	}
 
+	public function setSummarySystemPrompt(string $summarySystemPrompt): void {
+		$this->appConfig->setValueString(
+			Application::APP_ID,
+			'summary_system_prompt',
+			$summarySystemPrompt,
+			lazy: true
+		);
+	}
+
 	/**
 	 * @param string $userId
 	 * @param string $language
@@ -250,6 +274,9 @@ public function setAdminConfig(array $adminConfig): void {
 		if (isset($adminConfig['usage_storage_time'])) {
 			$this->setUsageStorageTime($adminConfig['usage_storage_time']);
 		}
+		if (isset($adminConfig['summary_system_prompt'])) {
+			$this->setSummarySystemPrompt($adminConfig['summary_system_prompt']);
+		}
 	}
 
 	/**
diff --git a/lib/TaskProcessing/ProviderFactory.php b/lib/TaskProcessing/ProviderFactory.php
index 43a2792e..2f2949e7 100644
--- a/lib/TaskProcessing/ProviderFactory.php
+++ b/lib/TaskProcessing/ProviderFactory.php
@@ -12,6 +12,7 @@
 use OCA\OpenAi\AppInfo\Application;
 use OCA\OpenAi\Service\ChunkService;
 use OCA\OpenAi\Service\OpenAiAPIService;
+use OCA\OpenAi\Service\OpenAiSettingsService;
 use OCA\OpenAi\Service\ServiceConfig;
 use OCA\OpenAi\Service\ServicesService;
 use OCA\OpenAi\Service\TranslateService;
@@ -35,6 +36,7 @@ class ProviderFactory {
 	public function __construct(
 		private ServicesService $servicesService,
 		private OpenAiAPIService $openAiAPIService,
+		private OpenAiSettingsService $openAiSettingsService,
 		private ChunkService $chunkService,
 		private TranslateService $translateService,
 		private WatermarkingService $watermarkingService,
@@ -80,7 +82,7 @@ private function getTextProviders(ServiceConfig $service, string $model): array
 			new TextToTextProvider($this->openAiAPIService, $this->l, $service, $model),
 			new TextToTextChatProvider($this->openAiAPIService, $this->l, $service, $model),
 			new TextToTextChatWithToolsProvider($this->openAiAPIService, $this->l, $service, $model),
-			new SummaryProvider($this->openAiAPIService, $this->l, $this->chunkService, $service, $model),
+			new SummaryProvider($this->openAiAPIService, $this->l, $this->chunkService, $this->openAiSettingsService, $service, $model),
 			new HeadlineProvider($this->openAiAPIService, $this->l, $service, $model),
 			new TopicsProvider($this->openAiAPIService, $this->l, $this->chunkService, $this->logger, $service, $model),
 			new ContextWriteProvider($this->openAiAPIService, $this->chunkService, $this->l, $service, $model),
diff --git a/lib/TaskProcessing/SummaryProvider.php b/lib/TaskProcessing/SummaryProvider.php
index f84709f5..63c1e140 100644
--- a/lib/TaskProcessing/SummaryProvider.php
+++ b/lib/TaskProcessing/SummaryProvider.php
@@ -11,6 +11,7 @@
 
 use OCA\OpenAi\Service\ChunkService;
 use OCA\OpenAi\Service\OpenAiAPIService;
+use OCA\OpenAi\Service\OpenAiSettingsService;
 use OCA\OpenAi\Service\ServiceConfig;
 use OCP\IL10N;
 use OCP\TaskProcessing\EShapeType;
@@ -28,6 +29,7 @@ public function __construct(
 		private OpenAiAPIService $openAiAPIService,
 		private IL10N $l,
 		private ChunkService $chunkService,
+		private OpenAiSettingsService $openAiSettingsService,
 		private ServiceConfig $service,
 		private string $model,
 	) {
@@ -142,8 +144,7 @@ public function process(?string $userId, array $input, callable $reportProgress)
 
 			try {
 				$completions = [];
-				$summarySystemPrompt = 'You are a helpful assistant that summarizes text in the same language as the text. '
-					. 'You should only return the summary without any additional information. ';
+				$summarySystemPrompt = $this->openAiSettingsService->getSummarySystemPrompt() . ' ';
 				if (isset($input['format'])) {
 					if ($input['format'] === 'paragraph') {
 						$summarySystemPrompt .= 'Return the summary as a paragraph. ';
diff --git a/src/components/AdminSettings.vue b/src/components/AdminSettings.vue
index 4503922c..91f9c0b6 100644
--- a/src/components/AdminSettings.vue
+++ b/src/components/AdminSettings.vue
@@ -58,6 +58,19 @@
 				</NcButton>
 			</div>
 
+			<h3>{{ t('integration_openai', 'Text generation') }}</h3>
+			<div class="line line--full">
+				<NcTextArea
+					id="summary-system-prompt"
+					v-model="state.summary_system_prompt"
+					class="input input--full"
+					:label="t('integration_openai', 'Summary system prompt')"
+					:helper-text="t('integration_openai', 'System prompt used when generating text summaries. Leave empty to use the default prompt.')"
+					:rows="5"
+					resize="vertical"
+					@update:model-value="onInput()" />
+			</div>
+
 			<h3>{{ t('integration_openai', 'Usage limits') }}</h3>
 			<div class="line">
 				<QuotaPeriodPicker
@@ -115,6 +128,7 @@ import NcInputField from '@nextcloud/vue/components/NcInputField'
 import NcLoadingIcon from '@nextcloud/vue/components/NcLoadingIcon'
 import NcNoteCard from '@nextcloud/vue/components/NcNoteCard'
 import NcSelect from '@nextcloud/vue/components/NcSelect'
+import NcTextArea from '@nextcloud/vue/components/NcTextArea'
 
 import axios from '@nextcloud/axios'
 import { showError, showSuccess, showWarning } from '@nextcloud/dialogs'
@@ -141,6 +155,7 @@ export default {
 		NcLoadingIcon,
 		NcNoteCard,
 		NcSelect,
+		NcTextArea,
 	},
 
 	data() {
@@ -415,6 +430,7 @@ export default {
 			await this.saveAdminConfig({
 				quota_period: this.state.quota_period,
 				usage_storage_time: parseInt(this.state.usage_storage_time) || 1,
+				summary_system_prompt: this.state.summary_system_prompt,
 			})
 		}, 2000),
 		async saveAdminConfig(values) {
@@ -475,6 +491,14 @@ export default {
 		width: 300px;
 	}
 
+	.line--full {
+		width: 100%;
+	}
+
+	.line .input--full {
+		width: 100%;
+	}
+
 	.services {
 		display: flex;
 		flex-wrap: wrap;
diff --git a/tests/unit/Providers/OpenAiProviderTest.php b/tests/unit/Providers/OpenAiProviderTest.php
index 5c5f9d02..81484cb8 100644
--- a/tests/unit/Providers/OpenAiProviderTest.php
+++ b/tests/unit/Providers/OpenAiProviderTest.php
@@ -539,10 +539,12 @@ public function testChangeToneProvider(): void {
 	}
 
 	public function testSummaryProvider(): void {
+		$this->openAiSettingsService->setSummarySystemPrompt('This is a custom summary system prompt');
 		$summaryProvider = new SummaryProvider(
 			$this->openAiApiService,
 			$this->createMock(\OCP\IL10N::class),
 			$this->chunkService,
+			$this->openAiSettingsService,
 			$this->service,
 			self::TEXT_MODEL,
 		);
@@ -576,8 +578,7 @@ public function testSummaryProvider(): void {
 		$url = self::OPENAI_API_BASE . 'chat/completions';
 
 		$options = ['timeout' => Application::OPENAI_DEFAULT_REQUEST_TIMEOUT, 'headers' => ['User-Agent' => Application::USER_AGENT, 'Authorization' => self::AUTHORIZATION_HEADER, 'Content-Type' => 'application/json']];
-		$systemPrompt = 'You are a helpful assistant that summarizes text in the same language as the text. '
-			. 'You should only return the summary without any additional information. ';
+		$systemPrompt = 'This is a custom summary system prompt ';
 		$options['body'] = json_encode([
 			'model' => Application::DEFAULT_COMPLETION_MODEL_ID,
 			'messages' => [