diff --git a/nselib/anyconnect.lua b/nselib/anyconnect.lua
index 912aa6e6f..ff86abc38 100644
--- a/nselib/anyconnect.lua
+++ b/nselib/anyconnect.lua
@@ -86,7 +86,7 @@ Cisco = {
       local path = '/'
       local response = http.head(self.host, self.port, path, options)
       -- account for redirects
-      if not response.status == 200 then
+      if response.status ~= 200 then
         return false, "Failed to connect to SSL VPN server"
       elseif response.location then
         local u = url.parse(response.location[#response.location])
diff --git a/nselib/bittorrent.lua b/nselib/bittorrent.lua
index f1708ac0a..0190b8e5c 100644
--- a/nselib/bittorrent.lua
+++ b/nselib/bittorrent.lua
@@ -1156,7 +1156,7 @@ Torrent =
     end
 
     -- the action in the response has to be 0 too
-    if not r_action == "00000000" then
+    if r_action ~= "00000000" then
       return false, "Wrong action field, usually caused by an erroneous request"
     end
 
diff --git a/scripts/broadcast-ping.nse b/scripts/broadcast-ping.nse
index 1c60d7662..5604f5033 100644
--- a/scripts/broadcast-ping.nse
+++ b/scripts/broadcast-ping.nse
@@ -222,7 +222,7 @@ action = function()
     -- single interface defined
     local interface = interface_opt or interface_arg
     local if_table = nmap.get_interface_info(interface)
-    if not if_table or not if_table.address or not if_table.link=="ethernet" then
+    if not (if_table and if_table.address and if_table.link=="ethernet") then
       stdnse.debug1("Interface not supported or not properly configured.")
       return false
     end
diff --git a/scripts/dns-fuzz.nse b/scripts/dns-fuzz.nse
index 89df0e819..d18482cce 100644
--- a/scripts/dns-fuzz.nse
+++ b/scripts/dns-fuzz.nse
@@ -193,7 +193,7 @@ function dropByte (dnsPacket)
   -- Iterate over every byte in the packet
   dnsPacket:gsub(".", function(c)
       i=i+1
-      if not i==byteToDrop then
+      if i ~= byteToDrop then
         newPacket[#newPacket+1] = c
       end
     end)
@@ -328,7 +328,7 @@ action = function(host, port)
     query =  makePacket ()
     -- induce random jitter
     retStr = corruptAndSend (host, port, query)
-    if not retStr==nil then
+    if retStr then
       return retStr
     end
   end
diff --git a/scripts/lltd-discovery.nse b/scripts/lltd-discovery.nse
index 25ffb06af..f36a33817 100644
--- a/scripts/lltd-discovery.nse
+++ b/scripts/lltd-discovery.nse
@@ -268,7 +268,7 @@ action = function()
     -- single interface defined
     local interface = interface_opt or interface_arg
     local if_table = nmap.get_interface_info(interface)
-    if not if_table or not if_table.address or not if_table.link=="ethernet" then
+    if not (if_table and if_table.address and if_table.link=="ethernet") then
       stdnse.debug1("Interface not supported or not properly configured.")
       return false
     end