diff --git a/scripts/prune_packets.py b/scripts/prune_packets.py
index 1c62196000bee95e0c01e148c60c3de54734dfe5..4d110db3c154f394ade9496209824abc4e45db0c 100755
--- a/scripts/prune_packets.py
+++ b/scripts/prune_packets.py
@@ -22,8 +22,8 @@ def pack_hdr_bytes(hdr):
 with open(args.outfile, 'wb') as fptr:
     idx = 0
     for pkt in stream.PacketStream(open(args.pdsfile)):
-        h1 = pkt._primary_header
-        h2 = pkt._secondary_header
+        h1 = pkt.primary_header
+        h2 = pkt.secondary_header
         if h2:
             h1.data_length_minus1 = c.sizeof(h2) - 1
             fptr.write(h1)