diff --git a/scripts/ssl-heartbleed.nse b/scripts/ssl-heartbleed.nse
index 7ea5a6da0..94eaeda84 100644
--- a/scripts/ssl-heartbleed.nse
+++ b/scripts/ssl-heartbleed.nse
@@ -1,9 +1,9 @@
-local bin = require('bin')
 local match = require('match')
 local nmap = require('nmap')
 local shortport = require('shortport')
 local sslcert = require('sslcert')
 local stdnse = require('stdnse')
+local string = require "string"
 local table = require('table')
 local vulns = require('vulns')
 local have_tls, tls = pcall(require,'tls')
@@ -54,7 +54,7 @@ local function recvhdr(s)
     stdnse.debug3('Unexpected EOF receiving record header - server closed connection')
     return
   end
-  local pos, typ, ver, ln = bin.unpack('>CSS', hdr)
+  local typ, ver, ln = string.unpack('>B I2 I2', hdr)
   return status, typ, ver, ln
 end
 
@@ -85,13 +85,12 @@ local function testversion(host, port, version)
     })
 
   local payload = "Nmap ssl-heartbleed"
-  local hb = tls.record_write("heartbeat", version, bin.pack("C>SA",
+  local hb = tls.record_write("heartbeat", version, string.pack("B>I2",
       1, -- HeartbeatMessageType heartbeat_request
-      0x4000, -- payload length (falsified)
+      0x4000) -- payload length (falsified)
       -- payload length is based on 4096 - 16 bytes padding - 8 bytes packet
       -- header + 1 to overflow
-      payload -- less than payload length.
-      )
+      .. payload -- less than payload length.
     )
 
   local status, s, err
diff --git a/scripts/ssl-known-key.nse b/scripts/ssl-known-key.nse
index 9575c6e09..5dd1fc150 100644
--- a/scripts/ssl-known-key.nse
+++ b/scripts/ssl-known-key.nse
@@ -2,9 +2,9 @@ local io = require "io"
 local nmap = require "nmap"
 local shortport = require "shortport"
 local stdnse = require "stdnse"
+local string = require "string"
 local sslcert = require "sslcert"
 local tls = require "tls"
-local bin = require "bin"
 
 -- -*- mode: lua -*-
 -- vim: set filetype=lua :
@@ -82,7 +82,7 @@ local get_fingerprints = function(path)
         section = line
       elseif section ~= nil then
         -- Add fingerprint to section.
-        local fingerprint = bin.pack("H", line)
+        local fingerprint = stdnse.fromhex(line)
         if #fingerprint == 20 then
           fingerprints[fingerprint] = section
           stdnse.debug4("Added key %s to database.", line)
diff --git a/scripts/tls-nextprotoneg.nse b/scripts/tls-nextprotoneg.nse
index d886826aa..f54166e09 100644
--- a/scripts/tls-nextprotoneg.nse
+++ b/scripts/tls-nextprotoneg.nse
@@ -1,8 +1,8 @@
 local nmap = require "nmap"
 local shortport = require "shortport"
 local stdnse = require "stdnse"
+local string = require "string"
 local table = require "table"
-local bin = require "bin"
 local sslcert = require "sslcert"
 local tls = require "tls"
 
@@ -124,10 +124,10 @@ local check_npn = function(response)
       return nil
     end
     -- Parse data
-    i = 0
+    i = 1
     local protocol
-    while i < #npndata do
-      i, protocol = bin.unpack(">p", npndata, i)
+    while i <= #npndata do
+      protocol, i = string.unpack(">s1", npndata, i)
       table.insert(results, protocol)
     end