diff --git a/moon/init.lua b/moon/init.lua
index 5d80e52..0ca497c 100644
--- a/moon/init.lua
+++ b/moon/init.lua
@@ -108,13 +108,11 @@ extend = function(...)
   return tbls[1]
 end
 copy = function(self)
-  return (function()
-    local _tbl_0 = { }
-    for key, val in pairs(self) do
-      _tbl_0[key] = val
-    end
-    return _tbl_0
-  end)()
+  local _tbl_0 = { }
+  for key, val in pairs(self) do
+    _tbl_0[key] = val
+  end
+  return _tbl_0
 end
 mixin = function(self, cls, ...)
   for key, val in pairs(cls.__base) do
diff --git a/moonscript/compile.lua b/moonscript/compile.lua
index 5892c20..83f95cd 100644
--- a/moonscript/compile.lua
+++ b/moonscript/compile.lua
@@ -119,16 +119,14 @@ do
       local strip
       strip = function(t)
         if "table" == type(t) then
-          return (function()
-            local _accum_0 = { }
-            local _len_0 = 1
-            for _index_0 = 1, #t do
-              local v = t[_index_0]
-              _accum_0[_len_0] = strip(v)
-              _len_0 = _len_0 + 1
-            end
-            return _accum_0
-          end)()
+          local _accum_0 = { }
+          local _len_0 = 1
+          for _index_0 = 1, #t do
+            local v = t[_index_0]
+            _accum_0[_len_0] = strip(v)
+            _len_0 = _len_0 + 1
+          end
+          return _accum_0
         else
           return t
         end
diff --git a/moonscript/transform.lua b/moonscript/transform.lua
index 09a8aa2..4287c1d 100644
--- a/moonscript/transform.lua
+++ b/moonscript/transform.lua
@@ -210,6 +210,18 @@ with_continue_listener = function(body)
 end
 do
   local _base_0 = {
+    transform_once = function(self, scope, node, ...)
+      if self.seen_nodes[node] then
+        return node
+      end
+      self.seen_nodes[node] = true
+      local transformer = self.transformers[ntype(node)]
+      if transformer then
+        return transformer(scope, node, ...) or node
+      else
+        return node
+      end
+    end,
     transform = function(self, scope, node, ...)
       if self.seen_nodes[node] then
         return node
@@ -314,6 +326,18 @@ Statement = Transformer({
   root_stms = function(self, body)
     return apply_to_last(body, implicitly_return(self))
   end,
+  ["return"] = function(self, node)
+    node[2] = Value:transform_once(self, node[2])
+    if "block_exp" == ntype(node[2]) then
+      local block_exp = node[2]
+      local block_body = block_exp[2]
+      local idx = #block_body
+      node[2] = block_body[idx]
+      block_body[idx] = node
+      return build.group(block_body)
+    end
+    return node
+  end,
   declare_glob = function(self, node)
     local names = extract_declarations(self)
     if node[2] == "^" then
@@ -370,7 +394,7 @@ Statement = Transformer({
           }
         })
       elseif "comprehension" == _exp_0 or "tblcomprehension" == _exp_0 or "foreach" == _exp_0 or "for" == _exp_0 or "while" == _exp_0 then
-        return build.assign_one(first_name, Value.transformers[first_value[1]](self, first_value))
+        return build.assign_one(first_name, Value:transform_once(self, first_value))
       end
     end
     local transformed
diff --git a/moonscript/transform.moon b/moonscript/transform.moon
index 0667197..a7fcab6 100644
--- a/moonscript/transform.moon
+++ b/moonscript/transform.moon
@@ -108,6 +108,16 @@ class Transformer
   new: (@transformers) =>
     @seen_nodes = setmetatable {}, __mode: "k"
 
+  transform_once: (scope, node, ...) =>
+    return node if @seen_nodes[node]
+    @seen_nodes[node] = true
+
+    transformer = @transformers[ntype node]
+    if transformer
+      transformer(scope, node, ...) or node
+    else
+      node
+
   transform: (scope, node, ...) =>
     return node if @seen_nodes[node]
     @seen_nodes[node] = true
@@ -158,6 +168,20 @@ Statement = Transformer {
   root_stms: (body) =>
     apply_to_last body, implicitly_return @
 
+  return: (node) =>
+    node[2] = Value\transform_once @, node[2]
+
+    if "block_exp" == ntype node[2]
+      block_exp = node[2]
+      block_body = block_exp[2]
+
+      idx = #block_body
+      node[2] = block_body[idx]
+      block_body[idx] = node
+      return build.group block_body
+
+    node
+
   declare_glob: (node) =>
     names = extract_declarations @
 
@@ -191,8 +215,7 @@ Statement = Transformer {
           }
 
         when "comprehension", "tblcomprehension", "foreach", "for", "while"
-          return build.assign_one first_name,
-            Value.transformers[first_value[1]] @, first_value
+          return build.assign_one first_name, Value\transform_once @, first_value
 
     -- bubble cascading assigns
     transformed = if num_values == 1
diff --git a/moonscript/util.lua b/moonscript/util.lua
index 7e5631d..dfb4355 100644
--- a/moonscript/util.lua
+++ b/moonscript/util.lua
@@ -77,15 +77,13 @@ split = function(str, delim)
     return { }
   end
   str = str .. delim
-  return (function()
-    local _accum_0 = { }
-    local _len_0 = 1
-    for m in str:gmatch("(.-)" .. delim) do
-      _accum_0[_len_0] = m
-      _len_0 = _len_0 + 1
-    end
-    return _accum_0
-  end)()
+  local _accum_0 = { }
+  local _len_0 = 1
+  for m in str:gmatch("(.-)" .. delim) do
+    _accum_0[_len_0] = m
+    _len_0 = _len_0 + 1
+  end
+  return _accum_0
 end
 local dump
 dump = function(what)
diff --git a/spec/outputs/bubbling.lua b/spec/outputs/bubbling.lua
index c0bc5fe..247ff1c 100644
--- a/spec/outputs/bubbling.lua
+++ b/spec/outputs/bubbling.lua
@@ -6,17 +6,15 @@ f = function(...)
 end
 local dont_bubble
 dont_bubble = function()
-  return (function()
-    local _accum_0 = { }
-    local _len_0 = 1
-    for x in (function(...)
-      return print(...)
-    end)("hello") do
-      _accum_0[_len_0] = x
-      _len_0 = _len_0 + 1
-    end
-    return _accum_0
-  end)()
+  local _accum_0 = { }
+  local _len_0 = 1
+  for x in (function(...)
+    return print(...)
+  end)("hello") do
+    _accum_0[_len_0] = x
+    _len_0 = _len_0 + 1
+  end
+  return _accum_0
 end
 local k
 do
@@ -44,21 +42,19 @@ do
 end
 local m
 m = function(...)
-  return (function(...)
-    local _accum_0 = { }
-    local _len_0 = 1
-    local _list_0 = {
-      ...
-    }
-    for _index_0 = 1, #_list_0 do
-      local x = _list_0[_index_0]
-      if f(...) > 4 then
-        _accum_0[_len_0] = x
-        _len_0 = _len_0 + 1
-      end
+  local _accum_0 = { }
+  local _len_0 = 1
+  local _list_0 = {
+    ...
+  }
+  for _index_0 = 1, #_list_0 do
+    local x = _list_0[_index_0]
+    if f(...) > 4 then
+      _accum_0[_len_0] = x
+      _len_0 = _len_0 + 1
     end
-    return _accum_0
-  end)(...)
+  end
+  return _accum_0
 end
 local x
 do
diff --git a/spec/outputs/lists.lua b/spec/outputs/lists.lua
index 7428af4..2846150 100644
--- a/spec/outputs/lists.lua
+++ b/spec/outputs/lists.lua
@@ -251,15 +251,13 @@ for _index_0 = a, _max_2 < 0 and #x + _max_2 or _max_2, c do
 end
 local normal
 normal = function(hello)
-  return (function()
-    local _accum_0 = { }
-    local _len_0 = 1
-    for x in yeah do
-      _accum_0[_len_0] = x
-      _len_0 = _len_0 + 1
-    end
-    return _accum_0
-  end)()
+  local _accum_0 = { }
+  local _len_0 = 1
+  for x in yeah do
+    _accum_0[_len_0] = x
+    _len_0 = _len_0 + 1
+  end
+  return _accum_0
 end
 local test = x(1, 2, 3, 4, 5)
 for _index_0 = 1, #test do
@@ -281,14 +279,12 @@ _ = function()
   end
 end
 return function()
-  return (function()
-    local _accum_0 = { }
-    local _len_0 = 1
-    for _index_0 = 1, #things do
-      x = things[_index_0]
-      _accum_0[_len_0] = x
-      _len_0 = _len_0 + 1
-    end
-    return _accum_0
-  end)()
+  local _accum_0 = { }
+  local _len_0 = 1
+  for _index_0 = 1, #things do
+    x = things[_index_0]
+    _accum_0[_len_0] = x
+    _len_0 = _len_0 + 1
+  end
+  return _accum_0
 end
\ No newline at end of file