diff -Naur mtools-4.0.10-orig/file_name.h mtools-4.0.10/file_name.h
--- mtools-4.0.10-orig/file_name.h	2009-02-19 22:41:14 +0200
+++ mtools-4.0.10/file_name.h	2009-07-20 13:42:26 +0300
@@ -26,8 +26,8 @@
  * MYFILE  TXT
  */
 struct dos_name_t {
-  char base[8];
-  char ext[3];
+  char base[9];
+  char ext[4];
   char sentinel;
 };
 
diff -Naur mtools-4.0.10-orig/mlabel.c mtools-4.0.10/mlabel.c
--- mtools-4.0.10-orig/mlabel.c	2009-03-03 08:10:11 +0200
+++ mtools-4.0.10/mlabel.c	2009-07-20 13:34:02 +0300
@@ -35,7 +35,8 @@
 	int have_lower, have_upper;
 	wchar_t wbuffer[12];
 
-	strcpy(ans->base,"           ");
+	strcpy(ans->base,"        ");
+	strcpy(ans->ext,"   ");
 	len = native_to_wchar(filename, wbuffer, 11, 0, 0);
 	if(len > 11){
 		*mangled = 1;