diff --git a/android/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineAppConfig.aidl b/android/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineAppConfig.aidl
index 5193e21..7db5135 100644
--- a/android/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineAppConfig.aidl
+++ b/android/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineAppConfig.aidl
@@ -23,7 +23,11 @@
     /** Name of VM */
     String name;
 
-    /** Id of the VM instance */
+    /**
+     * Id of the VM instance
+     *
+     * See AVirtualMachineRawConfig_setInstanceId for details.
+     */
     byte[64] instanceId;
 
     /** Main APK */
diff --git a/android/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineRawConfig.aidl b/android/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineRawConfig.aidl
index c5fe982..1e4fe03 100644
--- a/android/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineRawConfig.aidl
+++ b/android/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineRawConfig.aidl
@@ -31,7 +31,11 @@
     /** Name of VM */
     String name;
 
-    /** Id of the VM instance */
+    /**
+     * Id of the VM instance
+     *
+     * See AVirtualMachineRawConfig_setInstanceId for details.
+     */
     byte[64] instanceId;
 
     /** The kernel image, if any. */
diff --git a/android/virtualizationservice/src/aidl.rs b/android/virtualizationservice/src/aidl.rs
index 1646117..e26cd4f 100644
--- a/android/virtualizationservice/src/aidl.rs
+++ b/android/virtualizationservice/src/aidl.rs
@@ -489,6 +489,9 @@
         id.try_fill(&mut rand::thread_rng())
             .context("Failed to allocate instance_id")
             .or_service_specific_exception(-1)?;
+        // Randomly allocated IDs always start with all 7s to avoid colliding with statically
+        // assigned IDs.
+        id[..4].fill(0x77);
         let uid = get_calling_uid();
         info!("Allocated a VM's instance_id: {:?}..., for uid: {:?}", &hex::encode(id)[..8], uid);
         self.try_updating_sk_state(&id);