diff --git a/integration_tests/tests/block.rs b/integration_tests/tests/block.rs
index be7f1d1ba3..e238bf9c58 100644
--- a/integration_tests/tests/block.rs
+++ b/integration_tests/tests/block.rs
@@ -37,10 +37,10 @@ fn prepare_disk_img() -> NamedTempFile {
 #[test]
 fn mount_block() {
     let disk = prepare_disk_img();
-    let disk_path = disk.path().to_str().unwrap().to_string();
+    let disk_path = disk.path().to_str().unwrap();
     println!("disk={disk_path}");
 
-    let config = Config::new().extra_args(vec!["--rwdisk".to_string(), disk_path]);
+    let config = Config::new().extra_args(vec!["--block".to_string(), format!("{},ro", disk_path)]);
     let mut vm = TestVm::new(config).unwrap();
     assert_eq!(
         vm.exec_in_guest("mount -t ext4 /dev/vdb /mnt && echo 42")
@@ -56,7 +56,7 @@ fn resize() {
     let disk_path = disk.path().to_str().unwrap().to_string();
     println!("disk={disk_path}");
 
-    let config = Config::new().extra_args(vec!["--rwdisk".to_string(), disk_path]);
+    let config = Config::new().extra_args(vec!["--block".to_string(), disk_path]);
     let mut vm = TestVm::new(config).unwrap();
 
     // Check the initial block device size.
diff --git a/integration_tests/tests/fixture/mod.rs b/integration_tests/tests/fixture/mod.rs
index 12f71afdc0..5eaa7402eb 100644
--- a/integration_tests/tests/fixture/mod.rs
+++ b/integration_tests/tests/fixture/mod.rs
@@ -288,12 +288,12 @@ impl TestVm {
     /// Configures the VM rootfs to load from the guest_under_test assets.
     fn configure_rootfs(command: &mut Command, o_direct: bool) {
         let rootfs_and_option = format!(
-            "{}{}",
+            "{}{},ro,root",
             rootfs_path().to_str().unwrap(),
             if o_direct { ",o_direct=true" } else { "" }
         );
         command
-            .args(&["--root", &rootfs_and_option])
+            .args(&["--block", &rootfs_and_option])
             .args(&["--params", "init=/bin/delegate"]);
     }