diff --git a/nselib/asn1.lua b/nselib/asn1.lua
index 531bc7a36..5740b3811 100644
--- a/nselib/asn1.lua
+++ b/nselib/asn1.lua
@@ -401,7 +401,7 @@ ASN1Encoder = {
         val = math.floor(val/256)
       end
       if lsb > 127 then -- two's complement collision
-        valStr = valStr .. bin.pack("H", "00")
+        valStr = valStr .. "\0"
       end
 
       return string.reverse(valStr)
diff --git a/nselib/ldap.lua b/nselib/ldap.lua
index a38c81e3a..ae139184a 100644
--- a/nselib/ldap.lua
+++ b/nselib/ldap.lua
@@ -108,7 +108,7 @@ tagEncoder['table'] = function(self, val)
   for _, v in ipairs(val) do
     encVal = encVal .. encode(v) -- todo: buffer?
   end
-  local tableType = bin.pack("H", "30")
+  local tableType = "\x30"
   if (val["_snmp"]) then
     tableType = bin.pack("H", val["_snmp"])
   end
diff --git a/nselib/mongodb.lua b/nselib/mongodb.lua
index 2860e53be..7b933d702 100644
--- a/nselib/mongodb.lua
+++ b/nselib/mongodb.lua
@@ -88,16 +88,16 @@ local function _element_to_bson(key, value)
   if type(value) == 'string' then
     local cstring = bin.pack("z",value) -- null-terminated string
     local length = bin.pack("<i", cstring:len())
-    local op = bin.pack('H','02')
+    local op = "\x02"
     return true, op .. name .. length .. cstring
   elseif type(value) =='table' then
-    return true, bin.pack('H','02') .. name .. toBson(value)
+    return true, "\x02" .. name .. toBson(value)
   elseif type(value)== 'boolean' then
-    return true, bin.pack('H','08') + name + bin.pack('H',value and '01' or '00')
+    return true, "\x08" .. name .. (value and '\x01' or '\0')
   elseif type(value) == 'number' then
-    --return bin.pack('H','10').. name .. bin.pack("<i", value)
+    --return "\x10" .. name .. bin.pack("<i", value)
     -- Use 01 - double for - works better than 10
-    return true, bin.pack('H','01') .. name .. bin.pack("<d", value)
+    return true, '\x01' .. name .. bin.pack("<d", value)
   end
 
   local _ = ("cannot convert value of type %s to bson"):format(type(value))
@@ -140,7 +140,7 @@ function toBson(dict)
   end
   dbg("Packet length is %d",length)
   --Final pack
-  return true, bin.pack("I", length) .. elements .. bin.pack('H',"00")
+  return true, bin.pack("I", length) .. elements .. "\0"
 end
 
 -- Reads a null-terminated string. If length is supplied, it is just cut
diff --git a/nselib/msrpc.lua b/nselib/msrpc.lua
index 529b1d529..6b16f2e7c 100644
--- a/nselib/msrpc.lua
+++ b/nselib/msrpc.lua
@@ -1110,7 +1110,7 @@ function spoolss_write_printer(smbstate,printer_handle,data)
   local padding_len = 4 - math.fmod(#data,4)
   local data_padding = nil
   if not (padding_len == 4) then
-    data_padding = string.rep(bin.pack("H","00"),padding_len)
+    data_padding = string.rep('\0', padding_len)
   end
   local arguments = printer_handle ..  msrpctypes.marshall_int32(#data)
   --..  msrpctypes.marshall_int32(#data)
@@ -1189,7 +1189,7 @@ end
 --@return (status,lookup_result) If status is false, lookup_result contains an error string, otherwise it's a lookup response table.
 function epmapper_lookup(smbstate,handle)
   if handle == nil then -- if it's a first request, send a null handle
-    handle = bin.pack("H","0000000000000000000000000000000000000000")
+    handle = string.rep('\0', 20)
   end
   -- void ept_lookup(
   -- [in]            handle_t            h,
diff --git a/nselib/snmp.lua b/nselib/snmp.lua
index d7f830255..6dcf186ea 100644
--- a/nselib/snmp.lua
+++ b/nselib/snmp.lua
@@ -46,7 +46,7 @@ tagEncoder['table'] = function(self, val)
     encVal = encVal .. self:encode(v) -- todo: buffer?
   end
 
-  local tableType = bin.pack("H", "30")
+  local tableType = "\x30"
   if (val["_snmp"]) then
     tableType = bin.pack("H", val["_snmp"])
   end