diff --git a/src/vbox/vbox_common.c b/src/vbox/vbox_common.c
index 24cdd6eeb9..a62714e782 100644
--- a/src/vbox/vbox_common.c
+++ b/src/vbox/vbox_common.c
@@ -1939,7 +1939,7 @@ vboxDomainDefineXMLFlags(virConnectPtr conn, const char *xml, unsigned int flags
      * you can make changes to the machine setting
      */
     gVBoxAPI.UIMachine.GetId(machine, &mchiid);
-    gVBoxAPI.UISession.Open(data, &mchiid, machine);
+    gVBoxAPI.UISession.Open(data, machine);
     gVBoxAPI.UISession.GetMachine(data->vboxSession, &machine);
 
     vboxSetBootDeviceOrder(def, data, machine);
@@ -2712,7 +2712,7 @@ static int vboxDomainSetMemory(virDomainPtr dom, unsigned long memory)
         goto cleanup;
     }
 
-    rc = gVBoxAPI.UISession.Open(data, &iid, machine);
+    rc = gVBoxAPI.UISession.Open(data, machine);
     if (NS_FAILED(rc))
         goto cleanup;
 
@@ -2872,7 +2872,7 @@ static int vboxDomainSetVcpusFlags(virDomainPtr dom, unsigned int nvcpus,
     if (openSessionForMachine(data, dom->uuid, &iid, &machine) < 0)
         return -1;
 
-    rc = gVBoxAPI.UISession.Open(data, &iid, machine);
+    rc = gVBoxAPI.UISession.Open(data, machine);
     if (NS_SUCCEEDED(rc)) {
         gVBoxAPI.UISession.GetMachine(data->vboxSession, &machine);
         if (machine) {
@@ -4236,7 +4236,7 @@ vboxDomainAttachDeviceImpl(virDomainPtr dom,
         gVBoxAPI.machineStateChecker.Paused(state)) {
         rc = gVBoxAPI.UISession.OpenExisting(data, &iid, machine);
     } else {
-        rc = gVBoxAPI.UISession.Open(data, &iid, machine);
+        rc = gVBoxAPI.UISession.Open(data, machine);
     }
 
     if (NS_FAILED(rc))
@@ -4355,7 +4355,7 @@ static int vboxDomainDetachDevice(virDomainPtr dom, const char *xml)
         gVBoxAPI.machineStateChecker.Paused(state)) {
         rc = gVBoxAPI.UISession.OpenExisting(data, &iid, machine);
     } else {
-        rc = gVBoxAPI.UISession.Open(data, &iid, machine);
+        rc = gVBoxAPI.UISession.Open(data, machine);
     }
 
     if (NS_FAILED(rc))
@@ -5406,7 +5406,7 @@ vboxDomainSnapshotCreateXML(virDomainPtr dom,
     if (gVBoxAPI.machineStateChecker.Online(state)) {
         rc = gVBoxAPI.UISession.OpenExisting(data, &domiid, machine);
     } else {
-        rc = gVBoxAPI.UISession.Open(data, &domiid, machine);
+        rc = gVBoxAPI.UISession.Open(data, machine);
     }
 
     if (NS_SUCCEEDED(rc))
@@ -7225,7 +7225,7 @@ static int vboxDomainSnapshotDelete(virDomainSnapshotPtr snapshot,
         goto cleanup;
     }
 
-    rc = gVBoxAPI.UISession.Open(data, &domiid, machine);
+    rc = gVBoxAPI.UISession.Open(data, machine);
     if (NS_SUCCEEDED(rc))
         rc = gVBoxAPI.UISession.GetConsole(data->vboxSession, &console);
     if (NS_FAILED(rc)) {
diff --git a/src/vbox/vbox_storage.c b/src/vbox/vbox_storage.c
index f6ede700f9..96c079192d 100644
--- a/src/vbox/vbox_storage.c
+++ b/src/vbox/vbox_storage.c
@@ -573,7 +573,7 @@ static int vboxStorageVolDelete(virStorageVolPtr vol, unsigned int flags)
             break;
         }
 
-        if (NS_FAILED(gVBoxAPI.UISession.Open(data, &machineId, machine))) {
+        if (NS_FAILED(gVBoxAPI.UISession.Open(data, machine))) {
             vboxIIDUnalloc(&machineId);
             continue;
         }
diff --git a/src/vbox/vbox_tmpl.c b/src/vbox/vbox_tmpl.c
index 8f7a2a6512..3fbdf80aba 100644
--- a/src/vbox/vbox_tmpl.c
+++ b/src/vbox/vbox_tmpl.c
@@ -1061,7 +1061,7 @@ _machineSaveSettings(IMachine *machine)
 }
 
 static nsresult
-_sessionOpen(struct _vboxDriver *data, vboxIID *iid G_GNUC_UNUSED, IMachine *machine)
+_sessionOpen(struct _vboxDriver *data, IMachine *machine)
 {
     return machine->vtbl->LockMachine(machine, data->vboxSession, LockType_Write);
 }
diff --git a/src/vbox/vbox_uniformed_api.h b/src/vbox/vbox_uniformed_api.h
index 393e48827f..10f58a2fe7 100644
--- a/src/vbox/vbox_uniformed_api.h
+++ b/src/vbox/vbox_uniformed_api.h
@@ -227,7 +227,7 @@ typedef struct {
 
 /* Functions for ISession */
 typedef struct {
-    nsresult (*Open)(struct _vboxDriver *driver, vboxIID *iid, IMachine *machine);
+    nsresult (*Open)(struct _vboxDriver *driver, IMachine *machine);
     nsresult (*OpenExisting)(struct _vboxDriver *driver, vboxIID *iid, IMachine *machine);
     nsresult (*GetConsole)(ISession *session, IConsole **console);
     nsresult (*GetMachine)(ISession *session, IMachine **machine);