diff --git a/tests/backcompat_test/src/main.rs b/tests/backcompat_test/src/main.rs
index 4113881..a7fb074 100644
--- a/tests/backcompat_test/src/main.rs
+++ b/tests/backcompat_test/src/main.rs
@@ -117,10 +117,9 @@
         /* consoleIn */ None,
         None,
         Some(dump_dt),
-        None,
     )
     .context("Failed to create VM")?;
-    vm.start().context("Failed to start VM")?;
+    vm.start(None).context("Failed to start VM")?;
     info!("Started example VM.");
 
     // Wait for VM to finish
diff --git a/tests/early_vm_test/src/main.rs b/tests/early_vm_test/src/main.rs
index a3c80ca..7d630f8 100644
--- a/tests/early_vm_test/src/main.rs
+++ b/tests/early_vm_test/src/main.rs
@@ -96,7 +96,6 @@
         None, // console_out
         None, // log
         None, // dump_dt
-        None, // callback
     )
     .context("Failed to create VM")?;
 
diff --git a/tests/vm_accessor/accessor/src/run.rs b/tests/vm_accessor/accessor/src/run.rs
index 6dcc507..5bdb8f1 100644
--- a/tests/vm_accessor/accessor/src/run.rs
+++ b/tests/vm_accessor/accessor/src/run.rs
@@ -129,10 +129,9 @@
         None,                    /* console_in */
         Some(android_log_fd()?), /* log */
         None,                    /* dump_dt */
-        Some(Box::new(Callback {})),
     )
     .context("Failed to create VM")?;
-    vm.start().context("Failed to start VM")?;
+    vm.start(Some(Box::new(Callback {}))).context("Failed to start VM")?;
 
     info!("started IAccessor VM with CID {}", vm.cid());
 
diff --git a/tests/vmbase_example/src/main.rs b/tests/vmbase_example/src/main.rs
index cbe90d8..d427164 100644
--- a/tests/vmbase_example/src/main.rs
+++ b/tests/vmbase_example/src/main.rs
@@ -115,10 +115,9 @@
         /* consoleIn */ None,
         Some(log_writer),
         /* dump_dt */ None,
-        None,
     )
     .context("Failed to create VM")?;
-    vm.start().context("Failed to start VM")?;
+    vm.start(None).context("Failed to start VM")?;
     info!("Started example VM.");
 
     // Wait for VM to finish, and check that it shut down cleanly.