diff --git a/src/libcamera/pipeline/ipu3/cio2.h b/src/libcamera/pipeline/ipu3/cio2.h
index 963c2f6b93a4..3aa3a1ca8ef8 100644
--- a/src/libcamera/pipeline/ipu3/cio2.h
+++ b/src/libcamera/pipeline/ipu3/cio2.h
@@ -66,8 +66,6 @@ public:
 private:
 	void freeBuffers();
 
-	void cio2BufferReady(FrameBuffer *buffer);
-
 	std::unique_ptr<CameraSensor> sensor_;
 	std::unique_ptr<V4L2Subdevice> csi2_;
 	std::unique_ptr<V4L2VideoDevice> output_;