diff --git a/exec.c b/exec.c
index de1cf19154..0bf0a6e7eb 100644
--- a/exec.c
+++ b/exec.c
@@ -1064,9 +1064,11 @@ static uint16_t phys_section_add(PhysPageMap *map,
 
 static void phys_section_destroy(MemoryRegion *mr)
 {
+    bool have_sub_page = mr->subpage;
+
     memory_region_unref(mr);
 
-    if (mr->subpage) {
+    if (have_sub_page) {
         subpage_t *subpage = container_of(mr, subpage_t, iomem);
         object_unref(OBJECT(&subpage->iomem));
         g_free(subpage);