diff --git a/scripts/broadcast-igmp-discovery.nse b/scripts/broadcast-igmp-discovery.nse
index fd62796e2..a556b014b 100644
--- a/scripts/broadcast-igmp-discovery.nse
+++ b/scripts/broadcast-igmp-discovery.nse
@@ -7,6 +7,7 @@ local ipOps = require "ipOps"
 local target = require "target"
 local coroutine = require "coroutine"
 local string = require "string"
+local io = require "io"
 
 description = [[
 Discovers targets that have IGMP Multicast memberships and grabs interesting information.
diff --git a/scripts/murmur-version.nse b/scripts/murmur-version.nse
index 2726b2ec0..92bfb4a8e 100644
--- a/scripts/murmur-version.nse
+++ b/scripts/murmur-version.nse
@@ -1,6 +1,8 @@
 local bin = require "bin"
 local comm = require "comm"
+local nmap = require "nmap"
 local shortport = require "shortport"
+local string = require "string"
 
 description = [[
 Detects the Murmur service (server for the Mumble voice communication
@@ -34,7 +36,7 @@ See http://mumble.sourceforge.net/Protocol.
 -- 64740/tcp open  murmur  Murmur 1.2.4 (control port; users: 35; max. users: 100; bandwidth: 72000 b/s)
 -- 64740/udp open  murmur  Murmur 1.2.4 (voice port; users: 35; max. users: 100; bandwidth: 72000 b/s)
 
-author = "Marin Maržić"
+author = "Marin Marzic"
 license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
 categories = { "version" }
 
@@ -64,6 +66,7 @@ action = function(host, port)
     port.version.product = "Murmur"
     port.version.version = v_a .. "." .. v_b .. "." .. v_c
     -- Set extra info depending on protocol and set port state to "open" if UDP
+    local portinfo
     if port.protocol == "tcp" then
         portinfo = "control port"
     else
diff --git a/scripts/mysql-enum.nse b/scripts/mysql-enum.nse
index 452488e3a..3071ab65f 100644
--- a/scripts/mysql-enum.nse
+++ b/scripts/mysql-enum.nse
@@ -1,9 +1,11 @@
+local bin = require "bin"
 local brute = require "brute"
 local creds = require "creds"
 local mysql = require "mysql"
 local nmap = require "nmap"
 local shortport = require "shortport"
 local stdnse = require "stdnse"
+local string = require "string"
 
 local openssl = stdnse.silent_require "openssl"
 
@@ -75,6 +77,7 @@ Driver = {
 		end
 		stdnse.print_debug( "Trying %s ...", pass)
 		local auth_string = bin.pack("H","0000018d00000000") .. pass .. bin.pack("H","00504e5f5155454d4500"); -- old authentication method 
+		local err
 		status, err = self.socket:send(bin.pack("c",string.len(auth_string)-3) .. auth_string) --send initial auth
 		status, response = self.socket:receive_bytes(0)
 		if not status then