diff --git a/lib/Log/LogIterator.php b/lib/Log/LogIterator.php
index 046f23f6a..6a6569ad4 100644
--- a/lib/Log/LogIterator.php
+++ b/lib/Log/LogIterator.php
@@ -81,30 +81,45 @@ private function fillBuffer(): void {
 
 	#[\Override]
 	public function next(): void {
+		// End offset of a line spanning multiple chunks. Its chunks are dropped once searched
+		// and the whole line is read again at once when its start is found.
+		$lineEnd = null;
 		// Loop through each character of the file looking for new lines
 		while ($this->position >= 0) {
 			$newlinePos = strrpos($this->buffer, "\n");
 			if ($newlinePos !== false) {
-				if ($newlinePos + 1 === strlen($this->buffer)) {
+				if ($lineEnd === null && $newlinePos + 1 === strlen($this->buffer)) {
 					// try again with truncated buffer if it ends with newline, i.e. on first call
 					$this->buffer = substr($this->buffer, 0, $newlinePos);
 					continue;
 				}
-				$this->lastLine = substr($this->buffer, $newlinePos + 1);
+				$this->lastLine = $lineEnd === null
+					? substr($this->buffer, $newlinePos + 1)
+					: $this->readRange($this->position + $newlinePos + 1, $lineEnd);
 				$this->buffer = substr($this->buffer, 0, $newlinePos);
 				$this->currentKey++;
 				return;
 			} elseif ($this->position === 0) {
-				$this->lastLine = $this->buffer;
+				$this->lastLine = $lineEnd === null ? $this->buffer : $this->readRange(0, $lineEnd);
 				$this->buffer = '';
 				$this->currentKey++;
 				return;
 			} else {
+				// $lineEnd must stay null until the line has content, the trailing newline check relies on it
+				if ($this->buffer !== '') {
+					$lineEnd ??= $this->position + strlen($this->buffer);
+					$this->buffer = '';
+				}
 				$this->fillBuffer();
 			}
 		}
 	}
 
+	private function readRange(int $start, int $end): string {
+		fseek($this->handle, $start);
+		return (string)stream_get_contents($this->handle, $end - $start);
+	}
+
 	#[\Override]
 	public function valid(): bool {
 		if (!is_resource($this->handle)) {
diff --git a/tests/Unit/Log/LogIteratorTest.php b/tests/Unit/Log/LogIteratorTest.php
index 1c643d4a5..f39ae894d 100644
--- a/tests/Unit/Log/LogIteratorTest.php
+++ b/tests/Unit/Log/LogIteratorTest.php
@@ -8,6 +8,7 @@
 namespace OCA\LogReader\Tests\Unit\Log;
 
 use OCA\LogReader\Log\LogIterator;
+use PHPUnit\Framework\Attributes\DataProvider;
 use Test\TestCase;
 
 class LogIteratorTest extends TestCase {
@@ -23,6 +24,38 @@ private function getLogIterator(string $log) {
 		return new LogIterator($handle, \DateTime::ATOM, 'UTC');
 	}
 
+	private function getLogLine(string $reqId, int $length): string {
+		$emptyLine = json_encode(['reqId' => $reqId, 'level' => 3, 'message' => '']);
+		$line = json_encode(['reqId' => $reqId, 'level' => 3, 'message' => str_repeat('a', $length - strlen($emptyLine))]);
+		$this->assertSame($length, strlen($line));
+		return $line;
+	}
+
+	public static function trailingNewlineProvider(): array {
+		return [
+			'without trailing newline' => [''],
+			'with trailing newline' => ["\n"],
+		];
+	}
+
+	#[DataProvider(methodName: 'trailingNewlineProvider')]
+	public function testGetLinesSpanningMultipleChunks(string $trailingNewline): void {
+		// The first line starts at the beginning of the file. The last line and the trailing newline fill
+		// exactly two chunks, so the newline in front of the last line is the last byte of the next chunk.
+		$first = $this->getLogLine('1', 3 * LogIterator::CHUNK_SIZE + 17);
+		$middle = $this->getLogLine('2', 100);
+		$last = $this->getLogLine('3', 2 * LogIterator::CHUNK_SIZE - strlen($trailingNewline));
+		$log = $this->getLogIterator($first . "\n" . $middle . "\n" . $last . $trailingNewline);
+
+		$entries = iterator_to_array($log);
+
+		$this->assertSame([
+			json_decode($last, true),
+			json_decode($middle, true),
+			json_decode($first, true),
+		], $entries);
+	}
+
 	public function testGetLines() {
 		$log = $this->getLogIterator(
 			'{"reqId":"1","level":3,"time":"2019-11-04T18:50:57+00:00","remoteAddr":"127.0.0.1","user":"admin","app":"comments","method":"GET","url":"/settings/admin/logging","message":{"Exception":"RuntimeException","Message":"App class OCA\\\\Comments\\\\AppInfo\\\\Application is not setup via query() but directly","Code":0,"Trace":[{"file":"/srv/http/cloud/apps/comments/lib/AppInfo/Application.php","line":42,"function":"__construct","class":"OCP\\\\AppFramework\\\\App","type":"->","args":["comments",[]]},{"file":"/srv/http/cloud/apps/comments/appinfo/app.php","line":24,"function":"__construct","class":"OCA\\\\Comments\\\\AppInfo\\\\Application","type":"->","args":[]},{"file":"/srv/http/cloud/lib/private/legacy/app.php","line":260,"args":["/srv/http/cloud/apps/comments/appinfo/app.php"],"function":"require_once"},{"file":"/srv/http/cloud/lib/private/legacy/app.php","line":154,"function":"requireAppFile","class":"OC_App","type":"::","args":["comments"]},{"file":"/srv/http/cloud/lib/private/legacy/app.php","line":127,"function":"loadApp","class":"OC_App","type":"::","args":["comments"]},{"file":"/srv/http/cloud/lib/base.php","line":991,"function":"loadApps","class":"OC_App","type":"::","args":[]},{"file":"/srv/http/cloud/index.php","line":42,"function":"handleRequest","class":"OC","type":"::","args":[]}],"File":"/srv/http/cloud/lib/public/AppFramework/App.php","Line":77,"CustomMessage":"--"},"userAgent":"Mozilla","version":"18.0.0.1"}