diff --git a/programs/develop/mtdbg/mtdbg.asm b/programs/develop/mtdbg/mtdbg.asm
index 5d5c23763..f42ccf013 100644
--- a/programs/develop/mtdbg/mtdbg.asm
+++ b/programs/develop/mtdbg/mtdbg.asm
@@ -1200,7 +1200,8 @@ OnBacktrace:
     .next:
         mcall   SF_DEBUG, SSF_READ_MEMORY, [debuggee_pid], sizeof.STACK_FRAME, ebp
         cmp     eax, -1
-        jz      .done
+        mov     esi, read_mem_err
+        jz      .exit
 
         ; Save stack_frame_dump
         push    edi
@@ -1259,7 +1260,7 @@ OnBacktrace:
 
     .done:
         mov     esi, newline
- 
+
     .exit:
         call    put_message
         pop     ebp