diff --git a/src/drivers/virtio/transport/pci.rs b/src/drivers/virtio/transport/pci.rs
index 2f250bd525..53d3a3728d 100644
--- a/src/drivers/virtio/transport/pci.rs
+++ b/src/drivers/virtio/transport/pci.rs
@@ -690,14 +690,15 @@ fn read_caps(device: &PciDevice<PciConfigRegion>) -> Result<Vec<PciCap>, PciErro
 		})
 		.map(|addr| CapData::read(addr, device.access()).unwrap())
 		.filter(|cap| cap.cfg_type != CapCfgType::Pci)
-		.map(|cap| {
+		.flat_map(|cap| {
 			let slot = cap.bar;
-			let (addr, size) = device.memory_map_bar(slot, true).unwrap();
-			PciCap {
-				bar: VirtioPciBar::new(slot, addr.as_u64(), size.try_into().unwrap()),
-				dev_id: device_id,
-				cap,
-			}
+			device
+				.memory_map_bar(slot, true)
+				.map(|(addr, size)| PciCap {
+					bar: VirtioPciBar::new(slot, addr.as_u64(), size.try_into().unwrap()),
+					dev_id: device_id,
+					cap,
+				})
 		})
 		.collect::<Vec<_>>();