diff --git a/lib/private/Log/ExceptionSerializer.php b/lib/private/Log/ExceptionSerializer.php
index fb63ddf0a0e..fc9e4cc1bd0 100644
--- a/lib/private/Log/ExceptionSerializer.php
+++ b/lib/private/Log/ExceptionSerializer.php
@@ -208,14 +208,16 @@ class ExceptionSerializer {
 	}
 
 	private function removeValuesFromArgs($args, $values) {
-		foreach ($args as &$arg) {
+		$workArgs = [];
+		foreach ($args as $arg) {
 			if (in_array($arg, $values, true)) {
 				$arg = '*** sensitive parameter replaced ***';
 			} elseif (is_array($arg)) {
 				$arg = $this->removeValuesFromArgs($arg, $values);
 			}
+			$workArgs[] = $arg;
 		}
-		return $args;
+		return $workArgs;
 	}
 
 	private function encodeTrace($trace) {
diff --git a/tests/lib/Log/ExceptionSerializerTest.php b/tests/lib/Log/ExceptionSerializerTest.php
index eede081bda3..02d91b726e2 100644
--- a/tests/lib/Log/ExceptionSerializerTest.php
+++ b/tests/lib/Log/ExceptionSerializerTest.php
@@ -60,8 +60,9 @@ class ExceptionSerializerTest extends TestCase {
 			$secret = ['Secret'];
 			$this->emit([&$secret]);
 		} catch (\Exception $e) {
-			$this->serializer->serializeException($e);
+			$serializedData = $this->serializer->serializeException($e);
 			$this->assertSame(['Secret'], $secret);
+			$this->assertSame('*** sensitive parameters replaced ***', $serializedData['Trace'][0]['args'][0]);
 		}
 	}
 }