diff --git a/virtualsmartcard/src/vpicc/virtualsmartcard/utils.py b/virtualsmartcard/src/vpicc/virtualsmartcard/utils.py
index ead1f2e..0041aa6 100644
--- a/virtualsmartcard/src/vpicc/virtualsmartcard/utils.py
+++ b/virtualsmartcard/src/vpicc/virtualsmartcard/utils.py
@@ -290,20 +290,24 @@ class C_APDU(APDU):
         apdu = apdu + [0] * max(4-len(apdu), 0)
         
         self.CLA, self.INS, self.P1, self.P2 = apdu[:4] # case 1, 2, 3, 4
+        self.__extended_length = False
         if len(apdu) == 4:                              # case 1
             self.data = ""
         elif (len(apdu) >= 7) and (apdu[5] == 0):       # extended length apdu
-            self.Lc = (apdu[5]<<8) + apdu[6]
+            self.__extended_length = True
             if len(apdu) == 7:                          # case 2 extended length
-                self.data = ""
-            elif len(apdu) == 7 + self.Lc:              # case 3 extended length
-                self.data = apdu[7:]
-            elif len(apdu) == 7 + self.Lc + 3:          # case 4 extended length
-                self.data = apdu[7:-3]
                 self.Le = (apdu[-2]<<8) + apdu[-1]
-            else:
-                raise ValueError, "Invalid Lc value. Is %s, should be %s or %s" % (self.Lc,
-                    7 + self.Lc, 7 + self.Lc + 3)
+                self.data = ""
+            else:                                       # case 3, 4 extended length 
+                self.Lc = (apdu[5]<<8) + apdu[6]
+                if len(apdu) == 7 + self.Lc:            # case 3 extended length
+                    self.data = apdu[7:]
+                elif len(apdu) == 7 + self.Lc + 3:      # case 4 extended length
+                    self.Le = (apdu[-2]<<8) + apdu[-1]
+                    self.data = apdu[7:-3]
+                else:
+                    raise ValueError, "Invalid Lc value. Is %s, should be %s or %s" % (self.Lc,
+                        7 + self.Lc, 7 + self.Lc + 3)
         else:                                           # short apdu
             if len(apdu) == 5:                          # case 2 short apdu
                 self.Le = apdu[-1]
@@ -315,9 +319,9 @@ class C_APDU(APDU):
                 elif len(apdu) == 5 + self.Lc + 1:      # case 4
                     self.data = apdu[5:-1]
                     self.Le = apdu[-1]
-            else:
-                raise ValueError, "Invalid Lc value. Is %s, should be %s or %s" % (self.Lc,
-                    5 + self.Lc, 5 + self.Lc + 1)
+                else:
+                    raise ValueError, "Invalid Lc value. Is %s, should be %s or %s" % (self.Lc,
+                        5 + self.Lc, 5 + self.Lc + 1)
     
     CLA = _make_byte_property("CLA"); cla = CLA
     INS = _make_byte_property("INS"); ins = INS
@@ -326,6 +330,16 @@ class C_APDU(APDU):
     Lc = _make_byte_property("Lc");   lc = Lc
     Le = _make_byte_property("Le");   le = Le
     
+    @property
+    def effective_Le(self):
+        if hasattr(self, "_Le") and (self.Le == 0):
+            if self.__extended_length:
+                return 0xffff
+            else:
+                return 0xff
+        else:
+            return self.Le
+
     def _format_fields(self):
         fields = ["CLA", "INS", "P1", "P2"]
         if self.Lc > 0: