diff --git a/debugger.lua b/debugger.lua
index 1581d7f..8d638e3 100644
--- a/debugger.lua
+++ b/debugger.lua
@@ -1,11 +1,19 @@
-local function execDebug()
+local function copyObject(o)
+  local obj = {}
+  for k,v in pairs(o) do
+    obj[k] = v
+  end
+  return obj
+end
+
+local function execDebug(env)
   local input = io.input()
   local result = { pcall(input.read, input, "*l") }
   if not result[1] then
     return false, result[2]
   end
 
-  local func = load("return " .. result[2])
+  local func = load(result[2], "debug", "bt", env)
   if type(func) ~= "function" then
     return false, func
   end
@@ -13,10 +21,12 @@ local function execDebug()
   return pcall(func)
 end
 
-local function debugREPL(onResult)
+local function debugREPL(onResult, debugArgs)
+  local globalEnv = copyObject(_ENV)
+  globalEnv._debug = debugArgs
   local result, retval
   repeat
-    result, retval = execDebug()
+    result, retval = execDebug(globalEnv)
     if result and type(onResult) == "function" then
       onResult(retval)
     end