diff --git a/ChangeLog b/ChangeLog
index 3f8e0e8e..61e43528 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2009-05-06  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
+
+	Avoid std::bad_alloc for negative bencode string length.
+	* src/bencode.cc
+	
 2009-05-06  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
 
 	Supported segmented downloading with chunked transfer encoding and
diff --git a/src/bencode.cc b/src/bencode.cc
index 9b43261e..0fb39eb7 100644
--- a/src/bencode.cc
+++ b/src/bencode.cc
@@ -57,9 +57,9 @@ static void checkdelim(std::istream& ss, const char delim = ':')
 
 static std::string decoderawstring(std::istream& ss)
 {
-  size_t length;
+  int length;
   ss >> length;
-  if(!ss) {
+  if(!ss || length < 0) {
     throw RecoverableException("A positive integer expected but none found.");
   }
   // TODO check length, it must be less than or equal to INT_MAX