diff --git a/lib/Controller/AvatarController.php b/lib/Controller/AvatarController.php
index 7edebf977d..876f0dc22b 100644
--- a/lib/Controller/AvatarController.php
+++ b/lib/Controller/AvatarController.php
@@ -86,6 +86,7 @@ class AvatarController extends AEnvironmentAwareController {
 
 		$response = new FileDisplayResponse($file);
 		$response->addHeader('Content-Type', $file->getMimeType());
+		$response->addHeader('X-NC-IsCustomAvatar', $this->avatarService->isCustomAvatar($this->getRoom()) ? '1' : '0');
 		// Cache for 1 day
 		$response->cacheFor(60 * 60 * 24, false, true);
 		return $response;
diff --git a/lib/Service/AvatarService.php b/lib/Service/AvatarService.php
index 5dd942fc47..2a05137612 100644
--- a/lib/Service/AvatarService.php
+++ b/lib/Service/AvatarService.php
@@ -185,19 +185,26 @@ class AvatarService {
 			} elseif ($this->emojiHelper->isValidSingleEmoji(mb_substr($room->getName(), 0, 1))) {
 				$file = new InMemoryFile($token, $this->getEmojiAvatar($room->getName(), $darkTheme));
 			} elseif ($room->getType() === Room::TYPE_CHANGELOG) {
-				$file = new InMemoryFile($token, file_get_contents(__DIR__ . '/../../img/changelog.svg'));
+				$fileName = 'changelog.svg';
+				$file = new InMemoryFile($fileName, file_get_contents(__DIR__ . '/../../img/' . $fileName));
 			} elseif ($room->getObjectType() === 'file') {
-				$file = new InMemoryFile($token, file_get_contents(__DIR__ . '/../../img/icon-conversation-text-' . $colorTone . '.svg'));
+				$fileName = 'icon-conversation-text-' . $colorTone . '.svg';
+				$file = new InMemoryFile($fileName, file_get_contents(__DIR__ . '/../../img/' . $fileName));
 			} elseif ($room->getObjectType() === 'share:password') {
-				$file = new InMemoryFile($token, file_get_contents(__DIR__ . '/../../img/icon-conversation-password-' . $colorTone . '.svg'));
+				$fileName = 'icon-conversation-password-' . $colorTone . '.svg';
+				$file = new InMemoryFile($fileName, file_get_contents(__DIR__ . '/../../img/' . $fileName));
 			} elseif ($room->getObjectType() === 'emails') {
-				$file = new InMemoryFile($token, file_get_contents(__DIR__ . '/../../img/icon-conversation-mail-' . $colorTone . '.svg'));
+				$fileName = 'icon-conversation-mail-' . $colorTone . '.svg';
+				$file = new InMemoryFile($fileName, file_get_contents(__DIR__ . '/../../img/' . $fileName));
 			} elseif ($room->getType() === Room::TYPE_PUBLIC) {
-				$file = new InMemoryFile($token, file_get_contents(__DIR__ . '/../../img/icon-conversation-public-' . $colorTone . '.svg'));
+				$fileName = 'icon-conversation-public-' . $colorTone . '.svg';
+				$file = new InMemoryFile($fileName, file_get_contents(__DIR__ . '/../../img/' . $fileName));
 			} elseif ($room->getType() === Room::TYPE_ONE_TO_ONE_FORMER) {
-				$file = new InMemoryFile($token, file_get_contents(__DIR__ . '/../../img/icon-conversation-user-' . $colorTone . '.svg'));
+				$fileName = 'icon-conversation-user-' . $colorTone . '.svg';
+				$file = new InMemoryFile($fileName, file_get_contents(__DIR__ . '/../../img/' . $fileName));
 			} else {
-				$file = new InMemoryFile($token, file_get_contents(__DIR__ . '/../../img/icon-conversation-group-' . $colorTone . '.svg'));
+				$fileName = 'icon-conversation-group-' . $colorTone . '.svg';
+				$file = new InMemoryFile($fileName, file_get_contents(__DIR__ . '/../../img/' . $fileName));
 			}
 		}
 		return $file;
@@ -245,6 +252,11 @@ class AvatarService {
 		return '';
 	}
 
+	public function isCustomAvatar(Room $room): bool {
+		return $room->getAvatar() !== ''
+			|| $this->getFirstCombinedEmoji($room->getName());
+	}
+
 	public function deleteAvatar(Room $room): void {
 		try {
 			$folder = $this->appData->getFolder('room-avatar');
@@ -270,7 +282,11 @@ class AvatarService {
 
 	public function getAvatarVersion(Room $room): string {
 		$avatarVersion = $room->getAvatar();
-		[$version] = explode('.', $avatarVersion);
-		return $version;
+		if ($avatarVersion) {
+			[$version] = explode('.', $avatarVersion);
+			return $version;
+		}
+		$file = $this->getAvatar($room, null);
+		return substr(md5($file->getName()), 0, 8);
 	}
 }
diff --git a/tests/integration/features/bootstrap/FeatureContext.php b/tests/integration/features/bootstrap/FeatureContext.php
index 6276e1bbaf..924dac174c 100644
--- a/tests/integration/features/bootstrap/FeatureContext.php
+++ b/tests/integration/features/bootstrap/FeatureContext.php
@@ -1200,6 +1200,10 @@ class FeatureContext implements Context, SnippetAcceptingContext {
 			$xpectedAttributes = $formData->getColumnsHash()[0];
 			$actual = $this->getDataFromResponse($this->response);
 			foreach ($xpectedAttributes as $attribute => $expectedValue) {
+				if ($expectedValue === 'NOT_EMPTY') {
+					Assert::assertNotEmpty($actual[$attribute]);
+					continue;
+				}
 				Assert::assertEquals($expectedValue, $actual[$attribute]);
 			}
 		}
@@ -3485,4 +3489,27 @@ class FeatureContext implements Context, SnippetAcceptingContext {
 			Assert::assertEquals($statusCode, $response->getStatusCode(), $message);
 		}
 	}
+
+	/**
+	 * @Then The following headers should be set
+	 * @param TableNode $table
+	 * @throws \Exception
+	 */
+	public function theFollowingHeadersShouldBeSet(TableNode $table) {
+		foreach ($table->getTable() as $header) {
+			$headerName = $header[0];
+			$expectedHeaderValue = $header[1];
+			$returnedHeader = $this->response->getHeader($headerName)[0];
+			if ($returnedHeader !== $expectedHeaderValue) {
+				throw new \Exception(
+					sprintf(
+						"Expected value '%s' for header '%s', got '%s'",
+						$expectedHeaderValue,
+						$headerName,
+						$returnedHeader
+					)
+				);
+			}
+		}
+	}
 }
diff --git a/tests/integration/features/conversation/avatar.feature b/tests/integration/features/conversation/avatar.feature
index 00965c6e59..605eecbff0 100644
--- a/tests/integration/features/conversation/avatar.feature
+++ b/tests/integration/features/conversation/avatar.feature
@@ -17,6 +17,8 @@ Feature: conversation/avatar
       | roomName | room2 |
     When user "participant1" uploads file "/img/favicon.png" as avatar of room "room2" with 200
     Then the room "room2" has an avatar with 200
+    And The following headers should be set
+      | X-NC-IsCustomAvatar | 1 |
     And user "participant1" sees the following system messages in room "room2" with 200
       | room  | actorType     | actorId      | systemMessage        | message                          |
       | room2 | users         | participant1 | avatar_set           | You set the conversation picture |
@@ -27,6 +29,12 @@ Feature: conversation/avatar
       | room2 | users         | participant1 | avatar_removed       | You removed the conversation picture |
       | room2 | users         | participant1 | avatar_set           | You set the conversation picture     |
       | room2 | users         | participant1 | conversation_created | You created the conversation         |
+    And user "participant1" gets room "room2" with 200 (v4)
+      | avatarVersion |
+      | NOT_EMPTY |
+    Then the room "room2" has an avatar with 200
+    And The following headers should be set
+      | X-NC-IsCustomAvatar | 0 |
 
   Scenario: Get avatar of conversation without custom avatar (fallback)
     Given user "participant1" creates room "room3" (v4)
diff --git a/tests/php/Service/AvatarServiceTest.php b/tests/php/Service/AvatarServiceTest.php
index 97cfc80feb..44fa822aee 100644
--- a/tests/php/Service/AvatarServiceTest.php
+++ b/tests/php/Service/AvatarServiceTest.php
@@ -83,16 +83,19 @@ class AvatarServiceTest extends TestCase {
 	public function testGetAvatarVersion(string $avatar, string $expected): void {
 		/** @var Room|MockObject $room */
 		$room = $this->createMock(Room::class);
-		$room->expects($this->once())
-			->method('getAvatar')
+		$room->method('getAvatar')
 			->willReturn($avatar);
 		$actual = $this->service->getAvatarVersion($room);
-		$this->assertEquals($expected, $actual);
+		if ($expected === 'STRING WITH 8 CHARS') {
+			$this->assertEquals(8, strlen($actual));
+		} else {
+			$this->assertEquals($expected, $actual);
+		}
 	}
 
 	public function dataGetAvatarVersion(): array {
 		return [
-			['', ''],
+			['', 'STRING WITH 8 CHARS'],
 			['1', '1'],
 			['1.png', '1'],
 		];