diff --git a/src/libcamera/software_isp/software_isp.cpp b/src/libcamera/software_isp/software_isp.cpp
index b7651b7d..fdadf79e 100644
--- a/src/libcamera/software_isp/software_isp.cpp
+++ b/src/libcamera/software_isp/software_isp.cpp
@@ -358,6 +358,7 @@ void SoftwareIsp::stop()
 {
 	ispWorkerThread_.exit();
 	ispWorkerThread_.wait();
+	ispWorkerThread_.removeMessages(debayer_.get());
 
 	Thread::current()->dispatchMessages(Message::Type::InvokeMessage, this);