VERSION      |  2 +-
 doc/news.rst |  6 ++++++
 pyderasn.py  | 48 ++++++++++++++++++++++++------------------------

diff --git a/VERSION b/VERSION
index ae93b695fac83ee53e1e7fa1cafe3d225d0bd4f364d2af94be5abc0b693a9027..454e621a24f73c12a1dc8330a78fccc9553c4c6a2c47b6e630804f25d0d3e26e 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-4.7
+4.8
diff --git a/doc/news.rst b/doc/news.rst
index 3893a982abd4d0fd62d5130298f2b63c48abe78971ec31a087a075e8d79bbd02..5011eae2d5b15738c40388c7236a7a6a36785b6392237b13ca8f61743a7d01e9 100644
--- a/doc/news.rst
+++ b/doc/news.rst
@@ -1,6 +1,12 @@
 News
 ====
 
+.. _release4.8:
+
+4.8
+---
+* Minor decode speed improvements
+
 .. _release4.7:
 
 4.7
diff --git a/pyderasn.py b/pyderasn.py
index 774968dee5b0485689133b9267c7d7015044dac34202aeb220aba7ebc6f0612c..0c97144154de673a1d644bd32f556dbfa812fe5e87cdefa3d6b01c11aff498ba 100755
--- a/pyderasn.py
+++ b/pyderasn.py
@@ -1551,10 +1551,10 @@             if value is None:
                 self._value = default
 
     def _value_sanitize(self, value):
+        if isinstance(value, bool):
+            return value
         if issubclass(value.__class__, Boolean):
             return value._value
-        if isinstance(value, bool):
-            return value
         raise InvalidValueType((self.__class__, bool))
 
     @property
@@ -1800,10 +1800,10 @@             if self._value is None:
                 self._value = default
 
     def _value_sanitize(self, value):
-        if issubclass(value.__class__, Integer):
-            value = value._value
-        elif isinstance(value, integer_types):
+        if isinstance(value, integer_types):
             pass
+        elif issubclass(value.__class__, Integer):
+            value = value._value
         elif isinstance(value, str):
             value = self.specs.get(value)
             if value is None:
@@ -2155,8 +2155,6 @@             octets[i] = int(bits[i * 8:(i * 8) + 8], 2)
         return bit_len, bytes(octets)
 
     def _value_sanitize(self, value):
-        if issubclass(value.__class__, BitString):
-            return value._value
         if isinstance(value, (string_types, binary_type)):
             if (
                     isinstance(value, string_types) and
@@ -2197,6 +2195,8 @@             return self._bits2octets("".join(
                 ("1" if bit in bits else "0")
                 for bit in six_xrange(max(bits) + 1)
             ))
+        if issubclass(value.__class__, BitString):
+            return value._value
         raise InvalidValueType((self.__class__, binary_type, string_types))
 
     @property
@@ -2605,10 +2605,10 @@             num=tag_num,
         )
 
     def _value_sanitize(self, value):
-        if issubclass(value.__class__, OctetString):
-            value = value._value
-        elif isinstance(value, binary_type):
+        if isinstance(value, binary_type):
             pass
+        elif issubclass(value.__class__, OctetString):
+            value = value._value
         else:
             raise InvalidValueType((self.__class__, bytes))
         if not self._bound_min <= len(value) <= self._bound_max:
@@ -3708,10 +3708,6 @@             if self._value is None:
                 self._value = default
 
     def _value_sanitize(self, value):
-        if isinstance(value, self.__class__):
-            return value._value
-        if isinstance(value, datetime):
-            return value.strftime(self.fmt).encode("ascii")
         if isinstance(value, binary_type):
             try:
                 value_decoded = value.decode("ascii")
@@ -3725,6 +3721,10 @@                     raise DecodeError("invalid UTCTime format")
                 return value
             else:
                 raise DecodeError("invalid UTCTime length")
+        if isinstance(value, self.__class__):
+            return value._value
+        if isinstance(value, datetime):
+            return value.strftime(self.fmt).encode("ascii")
         raise InvalidValueType((self.__class__, datetime))
 
     def __eq__(self, their):
@@ -3810,12 +3810,6 @@     fmt = "%Y%m%d%H%M%SZ"
     fmt_ms = "%Y%m%d%H%M%S.%fZ"
 
     def _value_sanitize(self, value):
-        if isinstance(value, self.__class__):
-            return value._value
-        if isinstance(value, datetime):
-            return value.strftime(
-                self.fmt_ms if value.microsecond > 0 else self.fmt
-            ).encode("ascii")
         if isinstance(value, binary_type):
             try:
                 value_decoded = value.decode("ascii")
@@ -3842,6 +3836,12 @@                 raise DecodeError(
                     "invalid GeneralizedTime length",
                     klass=self.__class__,
                 )
+        if isinstance(value, self.__class__):
+            return value._value
+        if isinstance(value, datetime):
+            return value.strftime(
+                self.fmt_ms if value.microsecond > 0 else self.fmt
+            ).encode("ascii")
         raise InvalidValueType((self.__class__, datetime))
 
     def todatetime(self):
@@ -3967,8 +3967,6 @@             if value is None:
                 self._value = default_obj.copy()._value
 
     def _value_sanitize(self, value):
-        if isinstance(value, self.__class__):
-            return value._value
         if isinstance(value, tuple) and len(value) == 2:
             choice, obj = value
             spec = self.specs.get(choice)
@@ -3977,6 +3975,8 @@                 raise ObjUnknown(choice)
             if not isinstance(obj, spec.__class__):
                 raise InvalidValueType((spec,))
             return (choice, spec(obj))
+        if isinstance(value, self.__class__):
+            return value._value
         raise InvalidValueType((self.__class__, tuple))
 
     @property
@@ -4212,12 +4212,12 @@         self._value = None if value is None else self._value_sanitize(value)
         self.defined = None
 
     def _value_sanitize(self, value):
+        if isinstance(value, binary_type):
+            return value
         if isinstance(value, self.__class__):
             return value._value
         if isinstance(value, Obj):
             return value.encode()
-        if isinstance(value, binary_type):
-            return value
         raise InvalidValueType((self.__class__, Obj, binary_type))
 
     @property