diff --git a/drivers/vfio/pci/vfio_pci_priv.h b/drivers/vfio/pci/vfio_pci_priv.h
index 4830fb01a1ca..58b8d34c162c 100644
--- a/drivers/vfio/pci/vfio_pci_priv.h
+++ b/drivers/vfio/pci/vfio_pci_priv.h
@@ -48,8 +48,8 @@ static inline ssize_t vfio_pci_vga_rw(struct vfio_pci_core_device *vdev,
 }
 #endif
 
-long vfio_pci_ioeventfd(struct vfio_pci_core_device *vdev, loff_t offset,
-			uint64_t data, int count, int fd);
+int vfio_pci_ioeventfd(struct vfio_pci_core_device *vdev, loff_t offset,
+		       uint64_t data, int count, int fd);
 
 int vfio_pci_init_perm_bits(void);
 void vfio_pci_uninit_perm_bits(void);
diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c
index d5e9883c1eee..e352a033b4ae 100644
--- a/drivers/vfio/pci/vfio_pci_rdwr.c
+++ b/drivers/vfio/pci/vfio_pci_rdwr.c
@@ -412,8 +412,8 @@ static void vfio_pci_ioeventfd_thread(void *opaque, void *unused)
 	vfio_pci_ioeventfd_do_write(ioeventfd, ioeventfd->test_mem);
 }
 
-long vfio_pci_ioeventfd(struct vfio_pci_core_device *vdev, loff_t offset,
-			uint64_t data, int count, int fd)
+int vfio_pci_ioeventfd(struct vfio_pci_core_device *vdev, loff_t offset,
+		       uint64_t data, int count, int fd)
 {
 	struct pci_dev *pdev = vdev->pdev;
 	loff_t pos = offset & VFIO_PCI_OFFSET_MASK;