pyderasn.py | 4 ++--

diff --git a/pyderasn.py b/pyderasn.py
index c08e51380f2b4844c572560ff9d33e5cf20ebff6c2a211f50f0974f574206715..54af90025ce60480aadb331aaaa5dce2b81d711b4007f7662dc3c27ab065fb38 100755
--- a/pyderasn.py
+++ b/pyderasn.py
@@ -3832,7 +3832,7 @@         if isinstance(value, binary_type):
             try:
                 value_decoded = value.decode("ascii")
             except (UnicodeEncodeError, UnicodeDecodeError) as err:
-                raise DecodeError("invalid UTCTime encoding")
+                raise DecodeError("invalid UTCTime encoding: %r" % err)
             try:
                 self._strptime(value_decoded)
             except (TypeError, ValueError) as err:
@@ -3977,7 +3977,7 @@         if isinstance(value, binary_type):
             try:
                 value_decoded = value.decode("ascii")
             except (UnicodeEncodeError, UnicodeDecodeError) as err:
-                raise DecodeError("invalid GeneralizedTime encoding")
+                raise DecodeError("invalid GeneralizedTime encoding: %r" % err)
             try:
                 self._strptime(value_decoded)
             except (TypeError, ValueError) as err: