diff --git a/scripts/dns-zone-transfer.nse b/scripts/dns-zone-transfer.nse
index 62c2ebb2a..bbe037f88 100644
--- a/scripts/dns-zone-transfer.nse
+++ b/scripts/dns-zone-transfer.nse
@@ -227,7 +227,7 @@ function build_domain(host)
     abs_name = listop.reverse(abs_name)
 
     -- prepend each element with its length
-    while i <= table.getn(abs_name) do
+    while i <= #abs_name do
         buf = buf .. string.char(string.len(abs_name[i])) .. abs_name[i]
         i = i + 1
     end
diff --git a/scripts/http-wp-plugins.nse b/scripts/http-wp-plugins.nse
index cb931b693..8712bb05d 100644
--- a/scripts/http-wp-plugins.nse
+++ b/scripts/http-wp-plugins.nse
@@ -148,7 +148,7 @@ action = function(host, port)
   end
 
 
-  if table.getn(result) > 0 then
+  if #result > 0 then
     result.name = "search amongst the " .. plugin_count .. " most popular plugins"
     return stdnse.format_output(true, result)
   else
diff --git a/scripts/ms-sql-brute.nse b/scripts/ms-sql-brute.nse
index 74f82678b..1a04c76d7 100644
--- a/scripts/ms-sql-brute.nse
+++ b/scripts/ms-sql-brute.nse
@@ -101,7 +101,7 @@ local function create_instance_output_table( instance )
 			end
 		end
 		
-		if ( table.getn( credsOutput ) == 0 ) then
+		if ( #credsOutput == 0 ) then
 			table.insert( instanceOutput, "No credentials found" )
 		end
 	end
diff --git a/scripts/ms-sql-empty-password.nse b/scripts/ms-sql-empty-password.nse
index b0bdf7399..bf2b155de 100644
--- a/scripts/ms-sql-empty-password.nse
+++ b/scripts/ms-sql-empty-password.nse
@@ -152,7 +152,7 @@ local function process_instance( instance )
 		for _, message in ipairs( instance.ms_sql_empty ) do
 			table.insert( instanceOutput, message )
 		end
-		if ( nmap.verbosity() > 1 and table.getn( instance.ms_sql_empty ) == 0 ) then
+		if ( nmap.verbosity() > 1 and #instance.ms_sql_empty == 0 ) then
 			table.insert( instanceOutput, "'sa' account password is not blank." )
 		end
 	end
diff --git a/scripts/smtp-open-relay.nse b/scripts/smtp-open-relay.nse
index ae1000fbf..ced853df4 100644
--- a/scripts/smtp-open-relay.nse
+++ b/scripts/smtp-open-relay.nse
@@ -209,7 +209,7 @@ function go(host, port)
 		end
 	end
 	
-	for index = 1, table.getn(tests), 1 do
+	for index = 1, #tests do
 		status, response = do_request(socket, "RSET\r\n")
 
 		if not status then