diff --git a/include/libcamera/internal/pipeline_handler.h b/include/libcamera/internal/pipeline_handler.h
index 0d3808036..fb28a18d0 100644
--- a/include/libcamera/internal/pipeline_handler.h
+++ b/include/libcamera/internal/pipeline_handler.h
@@ -60,6 +60,7 @@ public:
 
 	bool completeBuffer(Request *request, FrameBuffer *buffer);
 	void completeRequest(Request *request);
+	void cancelRequest(Request *request);
 
 	std::string configurationFile(const std::string &subdir,
 				      const std::string &name) const;
diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
index 3ddce71d3..e862ef00f 100644
--- a/src/libcamera/pipeline/simple/simple.cpp
+++ b/src/libcamera/pipeline/simple/simple.cpp
@@ -284,6 +284,7 @@ public:
 	std::vector<std::unique_ptr<FrameBuffer>> conversionBuffers_;
 	std::queue<std::map<const Stream *, FrameBuffer *>> conversionQueue_;
 	bool useConversion_;
+	void clearIncompleteRequests();
 
 	std::unique_ptr<Converter> converter_;
 	std::unique_ptr<SoftwareIsp> swIsp_;
@@ -897,6 +898,18 @@ void SimpleCameraData::conversionOutputDone(FrameBuffer *buffer)
 		pipe->completeRequest(request);
 }
 
+void SimpleCameraData::clearIncompleteRequests()
+{
+	while (!conversionQueue_.empty()) {
+		for (auto &item : conversionQueue_.front()) {
+			FrameBuffer *outputBuffer = item.second;
+			Request *request = outputBuffer->request();
+			pipe()->cancelRequest(request);
+		}
+		conversionQueue_.pop();
+	}
+}
+
 void SimpleCameraData::ispStatsReady(uint32_t frame, uint32_t bufferId)
 {
 	swIsp_->processStats(frame, bufferId,
@@ -1407,6 +1420,7 @@ void SimplePipelineHandler::stopDevice(Camera *camera)
 	video->bufferReady.disconnect(data, &SimpleCameraData::bufferReady);
 
 	data->conversionBuffers_.clear();
+	data->clearIncompleteRequests();
 
 	releasePipeline(data);
 }
diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index e59404691..c9cb11f0f 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -367,9 +367,7 @@ void PipelineHandler::stop(Camera *camera)
 	while (!waitingRequests_.empty()) {
 		Request *request = waitingRequests_.front();
 		waitingRequests_.pop();
-
-		request->_d()->cancel();
-		completeRequest(request);
+		cancelRequest(request);
 	}
 
 	/* Make sure no requests are pending. */
@@ -470,10 +468,8 @@ void PipelineHandler::doQueueRequest(Request *request)
 	}
 
 	int ret = queueRequestDevice(camera, request);
-	if (ret) {
-		request->_d()->cancel();
-		completeRequest(request);
-	}
+	if (ret)
+		cancelRequest(request);
 }
 
 /**
@@ -568,6 +564,19 @@ void PipelineHandler::completeRequest(Request *request)
 	}
 }
 
+/**
+ * \brief Cancel request and signal its completion
+ * \param[in] request The request to cancel
+ *
+ * This function cancels the request in addition to its completion. The same
+ * rules as for completeRequest() apply.
+ */
+void PipelineHandler::cancelRequest(Request *request)
+{
+	request->_d()->cancel();
+	completeRequest(request);
+}
+
 /**
  * \brief Retrieve the absolute path to a platform configuration file
  * \param[in] subdir The pipeline handler specific subdirectory name