diff --git a/reader.c b/reader.c
index 75f5be9b9..d6ac49db2 100644
--- a/reader.c
+++ b/reader.c
@@ -1530,10 +1530,15 @@ void reader_sanity_check()
 {
 	if( is_interactive)
 	{
+		if( !data )
+			sanity_lose();
+
 		if(!( data->buff_pos <= data->buff_len ))
 			sanity_lose();
+
 		if(!( data->buff_len == wcslen( data->buff ) ))
 			sanity_lose();
+
 	}
 }