diff --git a/include/exec/memory.h b/include/exec/memory.h
index 358edfb..bec9756 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -628,6 +628,9 @@
  */
 static inline bool memory_region_is_iommu(MemoryRegion *mr)
 {
+    if (mr->alias) {
+        return memory_region_is_iommu(mr->alias);
+    }
     return mr->iommu_ops;
 }