diff --git a/mboxd_flash_virtual.cpp b/mboxd_flash_virtual.cpp
index fb4075f..26fe07a 100644
--- a/mboxd_flash_virtual.cpp
+++ b/mboxd_flash_virtual.cpp
@@ -186,7 +186,7 @@
     catch (InternalFailure& e)
     {
         commit<InternalFailure>();
-        rc = -1;
+        rc = -MBOX_R_SYSTEM_ERROR;
     }
     return rc;
 }