diff --git a/scripts/clock-skew.nse b/scripts/clock-skew.nse
index 0b123fdea..14f80d12e 100644
--- a/scripts/clock-skew.nse
+++ b/scripts/clock-skew.nse
@@ -1,4 +1,3 @@
-local coroutine = require "coroutine"
 local datetime = require "datetime"
 local formulas = require "formulas"
 local math = require "math"
diff --git a/scripts/smb-brute.nse b/scripts/smb-brute.nse
index edc2501cb..4931afb50 100644
--- a/scripts/smb-brute.nse
+++ b/scripts/smb-brute.nse
@@ -1063,9 +1063,7 @@ local function go(host)
   return true, hostinfo['accounts'], hostinfo['locked_usernames']
 end
 
---_G.TRACEBACK = TRACEBACK or {}
 action = function(host)
-  -- TRACEBACK[coroutine.running()] = true;
 
   local status, result
   local response = {}
diff --git a/scripts/smb-enum-sessions.nse b/scripts/smb-enum-sessions.nse
index dd3725d4d..495c583cb 100644
--- a/scripts/smb-enum-sessions.nse
+++ b/scripts/smb-enum-sessions.nse
@@ -266,9 +266,7 @@ local function winreg_enum_rids(host)
 end
 
 
---_G.TRACEBACK = TRACEBACK or {}
 action = function(host)
-  --    TRACEBACK[coroutine.running()] = true;
 
   local response = {}