diff --git a/nselib/asn1.lua b/nselib/asn1.lua
index 15874fd8b..2620024ef 100644
--- a/nselib/asn1.lua
+++ b/nselib/asn1.lua
@@ -454,7 +454,7 @@ function BERtoInt(class, constructed, number)
 
   local asn1_type = class + number
 
-  if constructed == true then
+  if constructed then
     asn1_type = asn1_type + 32
   end
 
diff --git a/nselib/brute.lua b/nselib/brute.lua
index 2c48f2eed..aad0c62e7 100644
--- a/nselib/brute.lua
+++ b/nselib/brute.lua
@@ -1145,7 +1145,7 @@ Engine = {
         end
       end
 
-      if stagnated == true then
+      if stagnated then
         stagnation_count = stagnation_count + 1
 
         -- If we get inside `if` below, then we are not making any
diff --git a/nselib/ipOps.lua b/nselib/ipOps.lua
index dbfd54622..35312886c 100644
--- a/nselib/ipOps.lua
+++ b/nselib/ipOps.lua
@@ -56,7 +56,7 @@ isPrivate = function( ip )
 
     for _, range in ipairs( ipv6_private ) do
       is_private, err = ip_in_range( ip, range )
-      if is_private == true then
+      if is_private then
         return true, range
       end
       if err then
@@ -79,7 +79,7 @@ isPrivate = function( ip )
   elseif ip:sub(1,4) == '172.' then
 
     local p, e = ip_in_range(ip, '172.16/12')
-    if p == true then
+    if p then
       return true, '172.16/12'
     else
       return p, e
diff --git a/nselib/msrpc.lua b/nselib/msrpc.lua
index cfad707de..f6bdffd88 100644
--- a/nselib/msrpc.lua
+++ b/nselib/msrpc.lua
@@ -473,7 +473,7 @@ function call_function(smbstate, opnum, arguments)
 
     -- No longer the 'first'
     first = false
-  until is_last == true
+  until is_last
 
   result['arguments'] = arguments
 
@@ -4148,13 +4148,13 @@ function lsa_enum_users(host)
 
   -- Get the server's name from nbstat
   local result, server_name = netbios.get_server_name(host.ip)
-  if(result == true) then
+  if result then
     names[#names + 1] = server_name
   end
 
   -- Get the logged in user from nbstat
   local result, user_name = netbios.get_user_name(host.ip)
-  if(result == true) then
+  if result then
     names[#names + 1] = user_name
   end
 
diff --git a/nselib/msrpctypes.lua b/nselib/msrpctypes.lua
index 31e56f466..9c5a60cd6 100644
--- a/nselib/msrpctypes.lua
+++ b/nselib/msrpctypes.lua
@@ -149,7 +149,7 @@ function string_to_unicode(string, do_null)
   local result = unicode.utf8to16(string)
 
   -- Add a null, if the caller requested it
-  if(do_null == true) then
+  if do_null then
     result = result .. "\0\0"
   end
 
@@ -338,7 +338,7 @@ local function unmarshall_ptr(location, data, pos, func, args, result)
   end
 
   if(location == BODY or location == ALL) then
-    if(result == true) then
+    if result then
       pos, result = func(data, pos, table.unpack(args))
     else
       result = nil
@@ -866,6 +866,7 @@ end
 --@param pad  [optional] If set, will remove extra bytes to align the packet, Default: true
 --@return (pos, int16) The new position, and the value.
 function unmarshall_int16(data, pos, pad)
+  if pad == nil then pad = true end
   local value
 
   stdnse.debug4("MSRPC: Entering unmarshall_int16()")
@@ -877,7 +878,7 @@ function unmarshall_int16(data, pos, pad)
   end
   value, pos = string.unpack("<I2", data, pos)
 
-  if(pad == nil or pad == true) then
+  if pad then
     pos = pos + 2
   end
 
@@ -893,6 +894,7 @@ end
 --@param pad  [optional] If set, will remove extra bytes to align the packet, Default: true
 --@return (pos, int8) The new position, and the value.
 function unmarshall_int8(data, pos, pad)
+  if pad == nil then pad = true end
   local value
 
   stdnse.debug4("MSRPC: Entering unmarshall_int8()")
@@ -904,7 +906,7 @@ function unmarshall_int8(data, pos, pad)
   end
   value, pos = string.unpack("<B", data, pos)
 
-  if(pad == nil or pad == true) then
+  if pad then
     pos = pos + 3
   end
 
@@ -1064,6 +1066,7 @@ end
 --            true.
 --@return (pos, str) The position, and the resulting string, which cannot be nil.
 function unmarshall_int8_array(data, pos, pad)
+  if pad == nil then pad = true end
   local max, offset, actual
   local str
 
@@ -1083,7 +1086,7 @@ function unmarshall_int8_array(data, pos, pad)
   str, pos = string.unpack("<c"..actual, data, pos)
 
   -- Do the alignment (note the "- 1", it's there because of 1-based arrays)
-  if(pad == nil or pad == true) then
+  if pad then
     while(((pos - 1) % 4) ~= 0) do
       pos = pos + 1
     end
diff --git a/nselib/punycode.lua b/nselib/punycode.lua
index ec389d45a..33b9247b0 100644
--- a/nselib/punycode.lua
+++ b/nselib/punycode.lua
@@ -91,13 +91,7 @@ end
 -- @param status boolean value is given as input.
 -- @return Returns 0/1 based on the given boolean input.
 local function boolToNum(status)
-
-  if status == true then
-    return 1
-  else
-    return 0
-  end
-
+  return status and 1 or 0
 end
 
 -- This function converts a basic code point into a digit/integer.
diff --git a/nselib/rpc.lua b/nselib/rpc.lua
index 1a4d86320..24d5e6830 100644
--- a/nselib/rpc.lua
+++ b/nselib/rpc.lua
@@ -463,7 +463,7 @@ Comm = {
 
         pos = pos + length
         data = bufcopy
-      until (lastfragment == true) or (retries == 0)
+      until lastfragment or retries == 0
 
       if retries == 0 then
         return false, "Aborted after too many retries"
diff --git a/nselib/smb.lua b/nselib/smb.lua
index 66a404e89..e15610b28 100644
--- a/nselib/smb.lua
+++ b/nselib/smb.lua
@@ -285,7 +285,7 @@ function start(host)
   nbcache_mutex "lock"
   if ( not(host.registry['netbios_name']) ) then
     status, result = netbios.get_server_name(host.ip)
-    if(status == true) then
+    if status then
       host.registry['netbios_name'] = result
       state['name'] = result
     end
@@ -363,11 +363,11 @@ function start_ex(host, bool_negotiate_protocol, bool_start_session, str_tree_co
   end
 
   -- Disable extended security if it was requested
-  if(bool_disable_extended == true) then
+  if bool_disable_extended then
     disable_extended(smbstate)
   end
 
-  if(bool_negotiate_protocol == true) then
+  if bool_negotiate_protocol then
     -- Negotiate the protocol
     status, err = negotiate_protocol(smbstate, overrides)
     if not status then
@@ -375,7 +375,7 @@ function start_ex(host, bool_negotiate_protocol, bool_start_session, str_tree_co
       return false, err
     end
 
-    if(bool_start_session == true) then
+    if bool_start_session then
       -- Start up a session
       status, err = start_session(smbstate, overrides)
       if not status then
@@ -523,7 +523,7 @@ function start_netbios(host, port, name)
 
   -- Get the name of the server from NetBIOS
   status, name = netbios.get_server_name(host.ip)
-  if(status == true) then
+  if status then
     names[#names + 1] = name
   end
 
@@ -657,7 +657,7 @@ function smb_encode_header(smb, command, overrides)
   end
 
 
-  if(smb['extended_security'] == true) then
+  if smb['extended_security'] then
     flags2 = (flags2 | 0x0800) -- SMB_EXTENDED_SECURITY
   end
 
@@ -834,6 +834,7 @@ end
 --        removed). If status is false, header contains an error message and parameters/
 --        data are undefined.
 function smb_read(smb, read_data)
+  if read_data == nil then read_data = true end
   local pos, netbios_data, netbios_length, length, header, parameter_length, parameters, data_length, data
 
   stdnse.debug3("SMB: Receiving SMB packet")
@@ -893,7 +894,7 @@ function smb_read(smb, read_data)
   data_length, pos = string.unpack("<I2", result, pos)
 
   -- Read that many bytes of data.
-  if(read_data == nil or read_data == true) then
+  if read_data then
     if (length - pos + 1) < data_length then
       return false, "SMB: ERROR: data_length greater than response length"
     end
@@ -1019,7 +1020,7 @@ function negotiate_v1(smb, overrides)
   end
 
   -- Data section
-  if(smb['extended_security'] == true) then
+  if smb['extended_security'] then
     if #data < 16 then
       return false, "SMB: ERROR: not enough data for extended security"
     end
@@ -1151,6 +1152,7 @@ end
 --- This is an internal function and should not be called externally. Use
 --  the start_session() function instead.
 local function start_session_basic(smb, log_errors, overrides)
+  if log_errors == nil then log_errors = true end
   local i, err
   local status, result
   local header, parameters, data, domain
@@ -1254,7 +1256,7 @@ local function start_session_basic(smb, log_errors, overrides)
       end
 
       -- Check if they were logged in as a guest
-      if(log_errors == nil or log_errors == true) then
+      if log_errors then
         if(smb['is_guest'] == 1) then
           stdnse.debug1("SMB: Login as %s\\%s failed, but was given guest access (username may be wrong, or system may only allow guest)", domain, stdnse.string_or_blank(username))
         else
@@ -1281,7 +1283,7 @@ local function start_session_basic(smb, log_errors, overrides)
         stdnse.sleep(backoff)
       else
         -- This username failed, print a warning and keep going
-        if(log_errors == nil or log_errors == true) then
+        if log_errors then
           stdnse.debug1("SMB: Login as %s\\%s failed (%s)", domain, stdnse.string_or_blank(username), get_status_name(status))
         end
 
@@ -1310,6 +1312,7 @@ end
 --- This is an internal function and should not be called externally. Use
 --  the start_session() function instead.
 local function start_session_extended(smb, log_errors, overrides)
+  if log_errors == nil then log_errors = true end
   local i
   local status, status_name, result, err
   local header, parameters, data
@@ -1493,7 +1496,7 @@ local function start_session_extended(smb, log_errors, overrides)
           end
 
           -- Check if they were logged in as a guest
-          if(log_errors == nil or log_errors == true) then
+          if log_errors then
             if(smb['is_guest'] == 1) then
               stdnse.debug1("SMB: Extended login to %s as %s\\%s failed, but was given guest access (username may be wrong, or system may only allow guest)", smb['ip'], domain, stdnse.string_or_blank(username))
             else
@@ -1522,7 +1525,7 @@ local function start_session_extended(smb, log_errors, overrides)
       stdnse.sleep(backoff)
     else
       -- Display a message to the user, and try the next account
-      if(log_errors == nil or log_errors == true) then
+      if log_errors then
         stdnse.debug1("SMB: Extended login to %s as %s\\%s failed (%s)", smb['ip'], domain, stdnse.string_or_blank(username), status_name)
       end
 
@@ -1543,7 +1546,7 @@ local function start_session_extended(smb, log_errors, overrides)
 
   end -- Loop over the accounts
 
-  if(log_errors == nil or log_errors == true) then
+  if log_errors then
     stdnse.debug1("SMB: ERROR: All logins failed, sorry it didn't work out!")
   end
 
@@ -1580,7 +1583,7 @@ function start_session(smb, overrides, log_errors)
   smb_auth_mutex( "lock" )
 
   local status, result
-  if(smb['extended_security'] == true) then
+  if smb['extended_security'] then
     status, result = start_session_extended(smb, log_errors, overrides)
   else
     status, result = start_session_basic(smb, log_errors, overrides)
@@ -3196,7 +3199,7 @@ function share_get_details(host, share)
   -- Check if the anonymous reader can read the share
   stdnse.debug1("SMB: Checking if share %s can be read by the anonymous user", share)
   status, result = share_anonymous_can_read(host, share)
-  if(status == true) then
+  if status then
     details['anonymous_can_read'] = result
   end
 
@@ -3217,7 +3220,7 @@ function share_get_details(host, share)
   status, result = share_anonymous_can_write(host, share)
   if not status and result == "NT_STATUS_OBJECT_NAME_NOT_FOUND" then
     details['anonymous_can_write'] = "NT_STATUS_OBJECT_NAME_NOT_FOUND"
-  elseif( status == true ) then
+  elseif status then
     details['anonymous_can_write'] = result
   end
 
@@ -3339,7 +3342,7 @@ function share_find_writable(host)
   end
 
   for i = 1, #shares, 1 do
-    if(shares[i]['user_can_write'] == true) then
+    if shares[i]['user_can_write'] then
       if(main_name == nil) then
         main_name = shares[i]['name']
 
@@ -3429,7 +3432,7 @@ function get_os(host)
   -- Start another session with extended security. This will allow us to get
   -- additional information about the target.
   status, smbstate = start_ex(host, true, true, nil, nil, false)
-  if(status == true) then
+  if status then
     -- See if we actually got something
     if (smbstate['fqdn'] or smbstate['domain_dns'] or smbstate['forest_dns']) then
       response['fqdn']         = smbstate['fqdn']
diff --git a/nselib/smb2.lua b/nselib/smb2.lua
index 4b60d0430..a709caaae 100644
--- a/nselib/smb2.lua
+++ b/nselib/smb2.lua
@@ -174,6 +174,7 @@ end
 ---
 function smb2_read(smb, read_data)
   stdnse.debug3("SMB2: Receiving SMB2 packet")
+  if read_data == nil then read_data = true end
 
   -- Receive the response -- we make sure to receive at least 4 bytes, the length of the NetBIOS length
   smb['socket']:set_timeout(TIMEOUT)
@@ -217,7 +218,7 @@ function smb2_read(smb, read_data)
 
   -- Read the data section or skip it if read_data is false.
   local data
-  if(read_data == nil or read_data == true) then
+  if read_data then
     data = result:sub(pos)
   end
 
diff --git a/nselib/ssh2.lua b/nselib/ssh2.lua
index 4a76a0d4a..4a9f99935 100644
--- a/nselib/ssh2.lua
+++ b/nselib/ssh2.lua
@@ -298,7 +298,7 @@ fetch_host_key = function( host, port, key_type )
   -- end
 
   local payload
-  if kexdh_gex_used == true then
+  if kexdh_gex_used then
     payload = transport.kexdh_gex_init( e )
   else
     payload = transport.kexdh_init( e )
diff --git a/nselib/vulns.lua b/nselib/vulns.lua
index 755ec1bbe..7cc7c39cf 100644
--- a/nselib/vulns.lua
+++ b/nselib/vulns.lua
@@ -634,7 +634,7 @@ end
 local filter_vulns = function(filters_db, vuln_table)
   local FIDS = {}
   for fid, callback in ipairs(filters_db) do
-    if callback(vuln_table) == true then
+    if callback(vuln_table) then
       FIDS[#FIDS + 1] = fid
     end
   end
diff --git a/scripts/broadcast-ospf2-discover.nse b/scripts/broadcast-ospf2-discover.nse
index 12fe9eda4..e02d91569 100644
--- a/scripts/broadcast-ospf2-discover.nse
+++ b/scripts/broadcast-ospf2-discover.nse
@@ -261,7 +261,7 @@ local ospfReplyDBDesc = function(interface, mac_dst, db_desc_in)
   local db_desc_out = ospf.OSPF.DBDescription:new()
   db_desc_out = ospfSetHeader(db_desc_in, db_desc_out)
 
-  if db_desc_in.init == true then
+  if db_desc_in.init then
     db_desc_out.init     = false
     db_desc_out.more     = db_desc_in.more
     db_desc_out.master   = false
diff --git a/scripts/eap-info.nse b/scripts/eap-info.nse
index a41eb05ae..49bccaeb0 100644
--- a/scripts/eap-info.nse
+++ b/scripts/eap-info.nse
@@ -170,7 +170,7 @@ action = function()
 
   local results = { ["name"] = ("Available authentication methods with identity=\"%s\" on interface %s"):format(identity.name, iface.device) }
   for i,v in pairs(identity.auth) do
-    if v== true then
+    if v then
       table.insert(results, 1, ("%-8s %s"):format(tostring(v), eap.eap_str[i] or "unassigned" ))
     else
       table.insert(results, ("%-8s %s"):format(tostring(v), eap.eap_str[i] or "unassigned" ))
diff --git a/scripts/http-jsonp-detection.nse b/scripts/http-jsonp-detection.nse
index 5acc12d3f..32b985f76 100644
--- a/scripts/http-jsonp-detection.nse
+++ b/scripts/http-jsonp-detection.nse
@@ -76,7 +76,7 @@ local callback_url = function(host, port, target, callback_variable)
     local status, func
     status, func = checkjson(response.body)
 
-    if status == true then
+    if status then
       if func == value then
         report = "Completely controllable from URL"
       else
@@ -102,7 +102,7 @@ local callback_bruteforce = function(host, port, target)
       local status, func
       status, func = checkjson(response.body)
 
-      if status == true then
+      if status then
         report = callback_url(host, port, target, p)
         if report ~= nil then
           report = string.format("%s\t%s", target, report)
@@ -152,7 +152,7 @@ action = function(host, port)
       local status, func, report
       status, func = checkjson(r.response.body)
 
-      if status == true then
+      if status then
         --We have found JSONP endpoint
         --Put it inside a returnable table.
         output_str = string.format("%s\n%s", output_str, target)
diff --git a/scripts/p2p-conficker.nse b/scripts/p2p-conficker.nse
index 800bd47fe..d046bde78 100644
--- a/scripts/p2p-conficker.nse
+++ b/scripts/p2p-conficker.nse
@@ -612,7 +612,7 @@ action = function(host)
     status, reason = conficker_check(host.ip, port, "tcp")
     checks = checks + 1
 
-    if(status == true) then
+    if status then
       table.insert(response, string.format("Check %d (port %d/%s): INFECTED (%s)", checks, port, "tcp", reason))
       count = count + 1
     else
@@ -627,7 +627,7 @@ action = function(host)
     status, reason = conficker_check(host.ip, port, "udp")
     checks = checks + 1
 
-    if(status == true) then
+    if status then
       table.insert(response, string.format("Check %d (port %d/%s): INFECTED (%s)", checks, port, "udp", reason))
       count = count + 1
     else
diff --git a/scripts/smb-brute.nse b/scripts/smb-brute.nse
index 51d8705f9..b514201fa 100644
--- a/scripts/smb-brute.nse
+++ b/scripts/smb-brute.nse
@@ -315,7 +315,7 @@ local function check_login(hostinfo, username, password, logintype)
     status, err = smb.start_session(smbstate, smb.get_overrides(username, domain, password, nil, logintype), false)
   end
 
-  if(status == true) then
+  if status then
     if(smbstate['is_guest'] == 1) then
       result = results.GUEST_ACCESS
     else
diff --git a/scripts/smb-enum-sessions.nse b/scripts/smb-enum-sessions.nse
index b71c8f5dd..803e08509 100644
--- a/scripts/smb-enum-sessions.nse
+++ b/scripts/smb-enum-sessions.nse
@@ -147,7 +147,7 @@ local function winreg_enum_rids(host)
   repeat
     local status, enumkey_result = msrpc.winreg_enumkey(smbstate, openhku_result['handle'], i, "")
 
-    if(status == true) then
+    if status then
       local status, openkey_result
 
       local element = {}
diff --git a/scripts/smb-system-info.nse b/scripts/smb-system-info.nse
index e23e89562..09710af5a 100644
--- a/scripts/smb-system-info.nse
+++ b/scripts/smb-system-info.nse
@@ -191,7 +191,7 @@ action = function(host)
 
   local response = {}
 
-  if(result['status-os'] == true) then
+  if result['status-os'] then
     local osdetails = {}
     osdetails['name'] = "OS Details"
     table.insert(osdetails, string.format("%s %s (%s %s build %s)",                     result['productname'], result['csdversion'], result['producttype'], result['currentversion'], result['currentbuildnumber']))
@@ -228,7 +228,7 @@ action = function(host)
     table.insert(response, browsers)
 
     return stdnse.format_output(true, response)
-  elseif(result['status-productname'] == true) then
+  elseif result['status-productname'] then
 
     local osdetails = {}
     osdetails['name'] = 'OS Details'
diff --git a/scripts/smb-vuln-conficker.nse b/scripts/smb-vuln-conficker.nse
index ebf330542..da3cf023d 100644
--- a/scripts/smb-vuln-conficker.nse
+++ b/scripts/smb-vuln-conficker.nse
@@ -122,7 +122,7 @@ function check_conficker(host)
   -- Try checking a valid string to find Conficker.D
   local netpathcanonicalize_result, error_result
   status, netpathcanonicalize_result, error_result = msrpc.srvsvc_netpathcanonicalize(smbstate, host.ip, "\\")
-  if(status == true and netpathcanonicalize_result['can_path'] == 0x5c45005c) then
+  if status and netpathcanonicalize_result['can_path'] == 0x5c45005c then
     msrpc.stop_smb(smbstate)
     return true, INFECTED2
   end
diff --git a/scripts/sniffer-detect.nse b/scripts/sniffer-detect.nse
index 0621f743f..7d543da3c 100644
--- a/scripts/sniffer-detect.nse
+++ b/scripts/sniffer-detect.nse
@@ -27,7 +27,7 @@ hostrule = function(host)
     stdnse.debug1("is IPv4 compatible only.")
     return false
   end
-  if host.directly_connected == true and
+  if host.directly_connected and
       host.mac_addr ~= nil and
       host.mac_addr_src ~= nil and
       host.interface ~= nil then
@@ -70,7 +70,7 @@ do_test = function(dnet, pcap, host, test)
     while status and test ~= check(layer2) do
       status, length, layer2, layer3 = pcap:pcap_receive()
     end
-    if status == true then
+    if status then
       -- the basic idea, was to inform user about time, when we got packet
       -- so that 1 would mean (0-10ms), 2=(10-40ms) and 3=(40ms-90ms)
       -- but when we're running this tests on macs, first test is always 2.
diff --git a/scripts/targets-sniffer.nse b/scripts/targets-sniffer.nse
index 7037469c3..842cf449c 100644
--- a/scripts/targets-sniffer.nse
+++ b/scripts/targets-sniffer.nse
@@ -120,7 +120,7 @@ action = function()
         stdnse.debug1("Got IP addresses %s", table.concat(addresses, " "))
 
         for _, addr in ipairs(addresses) do
-          if check_if_valid(addr) == true then
+          if check_if_valid(addr) then
             if not unique_addresses[addr] then
               unique_addresses[addr] = true
               table.insert(all_addresses, addr)
@@ -137,7 +137,7 @@ action = function()
     sock:pcap_close()
   end
 
-  if target.ALLOW_NEW_TARGETS == true then
+  if target.ALLOW_NEW_TARGETS then
     if nmap.address_family() == 'inet6' then
       for _,v in pairs(all_addresses) do
         if v:match(':') then
diff --git a/scripts/tftp-enum.nse b/scripts/tftp-enum.nse
index 831cbad66..6836ca91e 100644
--- a/scripts/tftp-enum.nse
+++ b/scripts/tftp-enum.nse
@@ -104,7 +104,7 @@ local generate_filenames = function(host)
       ::next_filename::
     end
 
-    if cisco == true then
+    if cisco then
       local cisco_address_confg_filenames = generate_cisco_address_confg(host.ip)
       return array_concat(default_filenames, cisco_address_confg_filenames)
     end
diff --git a/scripts/vulners.nse b/scripts/vulners.nse
index 1508d8f87..41bc2c25e 100644
--- a/scripts/vulners.nse
+++ b/scripts/vulners.nse
@@ -146,7 +146,7 @@ function get_results(what, vers, type)
 
   status, vulns = json.parse(response.body)
 
-  if status == true then
+  if status then
     if vulns.result == "OK" then
       return make_links(vulns)
     end