diff --git a/virtualsmartcard/src/vpicc/virtualsmartcard/SmartcardFilesystem.py b/virtualsmartcard/src/vpicc/virtualsmartcard/SmartcardFilesystem.py
index a21cc2f..935dd72 100644
--- a/virtualsmartcard/src/vpicc/virtualsmartcard/SmartcardFilesystem.py
+++ b/virtualsmartcard/src/vpicc/virtualsmartcard/SmartcardFilesystem.py
@@ -626,7 +626,7 @@ class MF(DF):
                 fdm.append("%c\x00" % TAG["SHORTFID"])
 
             if isinstance(file, TransparentStructureEF):
-                l = inttostring(len(file.data))
+                l = inttostring(len(file.data), 2, True)
                 fdm.append("%c%c%s" % (TAG["BYTES_EXCLUDINGSTRUCTURE"],
                            chr(len(l)), l))
                 fdm.append("%c%c%s" % (TAG["BYTES_INCLUDINGSTRUCTURE"],
@@ -643,9 +643,9 @@ class MF(DF):
                     else:
                         l += len(r.data)
                 fdm.append("%c\x02%s" % (TAG["BYTES_EXCLUDINGSTRUCTURE"],
-                           inttostring(l, 2)))
+                           inttostring(l, 2, True)))
                 fdm.append("%c\x02%s" % (TAG["BYTES_INCLUDINGSTRUCTURE"],
-                           inttostring(l, 2)))
+                           inttostring(l, 2, True)))
                 l = len(records)
                 fdm.append("%c\x06%c%c%c%c%s" % (TAG["FILEDISCRIPTORBYTE"],
                            file.filedescriptor, file.datacoding,
diff --git a/virtualsmartcard/src/vpicc/virtualsmartcard/utils.py b/virtualsmartcard/src/vpicc/virtualsmartcard/utils.py
index e4b6394..f589e63 100644
--- a/virtualsmartcard/src/vpicc/virtualsmartcard/utils.py
+++ b/virtualsmartcard/src/vpicc/virtualsmartcard/utils.py
@@ -27,7 +27,7 @@ def stringtoint(str):
     return 0
 
 
-def inttostring(i, length=None):
+def inttostring(i, length=None, len_extendable=False):
     str = "%x" % i
     if len(str) % 2 == 0:
         str = str.decode('hex')
@@ -36,7 +36,7 @@ def inttostring(i, length=None):
 
     if length:
         l = len(str)
-        if l > length:
+        if l > length and not len_extendable:
             raise ValueError("i too big for the specified stringlength")
         else:
             str = chr(0)*(length-l) + str