diff --git a/tools/dissectors/1-hfudt.lua b/tools/dissectors/1-hfudt.lua
index eeda0c4d7e..00b71a341a 100644
--- a/tools/dissectors/1-hfudt.lua
+++ b/tools/dissectors/1-hfudt.lua
@@ -313,7 +313,10 @@ function p_hfudt.dissector(buf, pinfo, tree)
 
     -- check if we have part of a message that we need to re-assemble
     -- before it can be dissected
-    if message_bit == 1 and message_position ~= 0 and message_number < 50 and message_part_number < 10 then
+    -- limit array indices to prevent lock-up with arbitrary data
+    if message_bit == 1 and message_position ~= 0 and message_number < 100
+      and message_part_number < 100 then
+
       if fragments[message_number] == nil then
         fragments[message_number] = {}
       end