diff --git a/include/libcamera/internal/software_isp/swstats_cpu.h b/include/libcamera/internal/software_isp/swstats_cpu.h
index b5348c6fe..c9ed1d0a6 100644
--- a/include/libcamera/internal/software_isp/swstats_cpu.h
+++ b/include/libcamera/internal/software_isp/swstats_cpu.h
@@ -56,7 +56,7 @@ public:
 	void setWindow(const Rectangle &window);
 	void startFrame(uint32_t frame);
 	void finishFrame(uint32_t frame, uint32_t bufferId);
-	void processFrame(uint32_t frame, uint32_t bufferId, FrameBuffer *input);
+	void processFrame(uint32_t frame, uint32_t bufferId, MappedFrameBuffer *input);
 
 	void processLine0(uint32_t frame, unsigned int y, const uint8_t *src[], unsigned int statsBufferIndex = 0)
 	{
diff --git a/src/libcamera/software_isp/debayer_egl.cpp b/src/libcamera/software_isp/debayer_egl.cpp
index 696498a58..d15f3cd48 100644
--- a/src/libcamera/software_isp/debayer_egl.cpp
+++ b/src/libcamera/software_isp/debayer_egl.cpp
@@ -555,7 +555,7 @@ void DebayerEGL::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output
 	metadata.planes()[0].bytesused = output->planes()[0].length;
 
 	/* Calculate stats for the whole frame */
-	stats_->processFrame(frame, 0, input);
+	stats_->processFrame(frame, 0, &in);
 	dmaSyncers.clear();
 
 	egl_.syncOutput();
diff --git a/src/libcamera/software_isp/swstats_cpu.cpp b/src/libcamera/software_isp/swstats_cpu.cpp
index 0815ec9a3..b182a1a2b 100644
--- a/src/libcamera/software_isp/swstats_cpu.cpp
+++ b/src/libcamera/software_isp/swstats_cpu.cpp
@@ -543,23 +543,16 @@ void SwStatsCpu::processBayerFrame2(MappedFrameBuffer &in)
  *
  * This may only be called after a successful setWindow() call.
  */
-void SwStatsCpu::processFrame(uint32_t frame, uint32_t bufferId, FrameBuffer *input)
+void SwStatsCpu::processFrame(uint32_t frame, uint32_t bufferId, MappedFrameBuffer *input)
 {
-	if (frame % kStatPerNumFrames) {
+	if (!input || frame % kStatPerNumFrames) {
 		finishFrame(frame, bufferId);
 		return;
 	}
 
 	bench_.startFrame();
 	startFrame(frame);
-
-	MappedFrameBuffer in(input, MappedFrameBuffer::MapFlag::Read);
-	if (!in.isValid()) {
-		LOG(SwStatsCpu, Error) << "mmap-ing buffer(s) failed";
-		return;
-	}
-
-	(this->*processFrame_)(in);
+	(this->*processFrame_)(*input);
 	finishFrame(frame, bufferId);
 	bench_.finishFrame();
 }