diff --git a/filters.cpp b/filters.cpp
index 95654b47..dcc65f5d 100644
--- a/filters.cpp
+++ b/filters.cpp
@@ -700,8 +700,8 @@ void StreamTransformationFilter::LastPut(const byte *inString, size_t length)
 		break;
 
 	case PKCS_PADDING:
-	case ONE_AND_ZEROS_PADDING:
 	case W3C_PADDING:
+	case ONE_AND_ZEROS_PADDING:
 		unsigned int s;
 		s = m_cipher.MandatoryBlockSize();
 		CRYPTOPP_ASSERT(s > 1);
@@ -713,9 +713,15 @@ void StreamTransformationFilter::LastPut(const byte *inString, size_t length)
 			if (m_padding == PKCS_PADDING)
 			{
 				CRYPTOPP_ASSERT(s < 256);
-				byte pad = byte(s-length);
+				byte pad = static_cast<byte>(s-length);
 				memset(space+length, pad, s-length);
 			}
+			else if (m_padding == W3C_PADDING)
+			{
+				CRYPTOPP_ASSERT(s < 256);
+				memset(space+length, 0, s-length-1);
+				space[s-1] = static_cast<byte>(s-length);
+			}
 			else
 			{
 				space[length] = 0x80;
diff --git a/filters.h b/filters.h
index 8851dfdb..a079fdba 100644
--- a/filters.h
+++ b/filters.h
@@ -480,7 +480,7 @@ struct BlockPaddingSchemeDef
 		PKCS_PADDING,
 		//! \brief 1 and 0's padding added to a block
 		ONE_AND_ZEROS_PADDING,
-		//! \brief [Random bytes (0 ~ N-2) and padding's length (N-1)]'s padding to a block
+		//! \brief W3C padding added to a block
 		W3C_PADDING,
 		//! \brief Default padding scheme
 		DEFAULT_PADDING