diff --git a/channels/smartcard/client/smartcard_pack.c b/channels/smartcard/client/smartcard_pack.c
index 4bd7fa66c..11c5dd562 100644
--- a/channels/smartcard/client/smartcard_pack.c
+++ b/channels/smartcard/client/smartcard_pack.c
@@ -470,7 +470,12 @@ UINT32 smartcard_pack_list_readers_return(SMARTCARD_DEVICE* smartcard, wStream*
 	Stream_Write_UINT32(s, ret->cBytes); /* cBytes (4 bytes) */
 	Stream_Write_UINT32(s, 0x00020008); /* mszNdrPtr (4 bytes) */
 	Stream_Write_UINT32(s, ret->cBytes); /* mszNdrLen (4 bytes) */
-	Stream_Write(s, ret->msz, ret->cBytes);
+	
+	if (ret->msz)
+		Stream_Write(s, ret->msz, ret->cBytes);
+	else
+		Stream_Zero(s, ret->cBytes);
+	
 	smartcard_pack_write_offset_align(smartcard, s, 4);
 
 	return SCARD_S_SUCCESS;
@@ -973,7 +978,12 @@ UINT32 smartcard_pack_status_return(SMARTCARD_DEVICE* smartcard, wStream* s, Sta
 	Stream_Write_UINT32(s, ret->cbAtrLen); /* cbAtrLen (4 bytes) */
 
 	Stream_Write_UINT32(s, ret->cBytes); /* mszReaderNamesNdrLen (4 bytes) */
-	Stream_Write(s, ret->mszReaderNames, ret->cBytes);
+	
+	if (ret->mszReaderNames)
+		Stream_Write(s, ret->mszReaderNames, ret->cBytes);
+	else
+		Stream_Zero(s, ret->cBytes);
+	
 	smartcard_pack_write_offset_align(smartcard, s, 4);
 
 	return SCARD_S_SUCCESS;