diff --git a/src/kernel/desktop-sa.c b/src/kernel/desktop-sa.c
index 31e320e6..07979b93 100644
--- a/src/kernel/desktop-sa.c
+++ b/src/kernel/desktop-sa.c
@@ -102,13 +102,14 @@ static BOOL InitWndManagementInfo (void)
 
 BOOL mg_InitDesktop (void)
 {
+    int ret;
     RECT rcScr = GetScreenRect();
 
     /*
      * Init ZOrderInfo here.
      */
-    __mg_zorder_info = kernel_alloc_z_order_info (DEF_NR_TOPMOSTS, DEF_NR_NORMALS);
-    if (__mg_zorder_info == NULL) {
+    ret = kernel_alloc_z_order_info (DEF_NR_TOPMOSTS, DEF_NR_NORMALS);
+    if (ret < 0) {
         _WRN_PRINTF ("KERNEL>Desktop: Can not initialize ZOrderInfo!\n");
         return FALSE;
     }
diff --git a/src/kernel/desktop-ths.c b/src/kernel/desktop-ths.c
index a3a1e91d..b1009e4b 100644
--- a/src/kernel/desktop-ths.c
+++ b/src/kernel/desktop-ths.c
@@ -110,11 +110,13 @@ static BOOL InitWndManagementInfo (void)
 
 BOOL mg_InitDesktop (void)
 {
+    int ret;
+
     /*
      * Init ZOrderInfo here.
      */
-    __mg_zorder_info = kernel_alloc_z_order_info (DEF_NR_TOPMOSTS, DEF_NR_NORMALS);
-    if (__mg_zorder_info == NULL) {
+    ret = kernel_alloc_z_order_info (DEF_NR_TOPMOSTS, DEF_NR_NORMALS);
+    if (ret < 0) {
         _WRN_PRINTF ("KERNEL>Desktop: Can not initialize ZOrderInfo!\n");
         return FALSE;
     }