diff --git a/performance-metrics/src/performance_tests.rs b/performance-metrics/src/performance_tests.rs
index 7dcf443d3..6e84fdd8e 100644
--- a/performance-metrics/src/performance_tests.rs
+++ b/performance-metrics/src/performance_tests.rs
@@ -413,6 +413,12 @@ pub fn performance_block_io(control: &PerformanceTestControl) -> f64 {
         .unwrap()
         .to_string();
 
+    let mut test_disk_arg =
+        format!("path={test_file},queue_size={queue_size},num_queues={num_queues}");
+    if test_file == OVERLAY_WITH_QCOW2_BACKING || test_file == OVERLAY_WITH_RAW_BACKING {
+        test_disk_arg.push_str(",backing_files=on");
+    }
+
     let mut child = GuestCommand::new(&guest)
         .args(["--cpus", &format!("boot={num_queues}")])
         .args(["--memory", "size=4G"])
@@ -430,7 +436,7 @@ pub fn performance_block_io(control: &PerformanceTestControl) -> f64 {
                 guest.disk_config.disk(DiskType::CloudInit).unwrap()
             )
             .as_str(),
-            format!("path={test_file},queue_size={queue_size},num_queues={num_queues}").as_str(),
+            test_disk_arg.as_str(),
         ])
         .default_net()
         .args(["--api-socket", &api_socket])