diff --git a/devices/memctrl/memctrlbase.cpp b/devices/memctrl/memctrlbase.cpp
index 0815d1b..02df57d 100644
--- a/devices/memctrl/memctrlbase.cpp
+++ b/devices/memctrl/memctrlbase.cpp
@@ -200,8 +200,6 @@ bool MemCtrlBase::add_mem_mirror_common(uint32_t start_addr, uint32_t dest_addr,
     if (!ref_entry)
         return false;
 
-    entry = new AddressMapEntry;
-
     // use origin's size if no size was specified
     if (!size)
         size = ref_entry->end - ref_entry->start + 1;
@@ -212,6 +210,8 @@ bool MemCtrlBase::add_mem_mirror_common(uint32_t start_addr, uint32_t dest_addr,
         return false;
     }
 
+    entry = new AddressMapEntry;
+
     uint32_t end   = start_addr + size - 1;
     entry->start   = start_addr;
     entry->end     = end;