diff --git a/sender.c b/sender.c
index db428560..e771a9e7 100644
--- a/sender.c
+++ b/sender.c
@@ -204,8 +204,7 @@ void send_files(struct file_list *flist, int f_out, int f_in)
 			iflags = ITEM_UPDATING | ITEM_MISSING_DATA;
 
 		if (inplace && protocol_version >= 29) {
-			uchar fnamecmp_type = read_byte(f_in);
-			updating_basis_file = fnamecmp_type == FNAMECMP_FNAME;
+			updating_basis_file = iflags & ITEM_USING_ALT_BASIS;
 		} else
 			updating_basis_file = inplace && !make_backups;