diff --git a/ldoc/doc.lua b/ldoc/doc.lua
index 9e4f430..46b381c 100644
--- a/ldoc/doc.lua
+++ b/ldoc/doc.lua
@@ -665,15 +665,21 @@ function build_arg_list (names,pmods)
    local function acc(x) table.insert(buffer, x) end
    for i = 1, #names  do
       local m = pmods and pmods[i]
+      local opt
       if m then
          if not m.optchain then
             acc ((']'):rep(npending))
             npending=0
          end
-         if m.opt or m.optchain then acc(' ['); npending=npending+1 end
+         opt = m.opt or m.optchain
+         if opt then
+            acc(' [')
+            npending=npending+1
+         end
       end
       if i>1 then acc (', ') end
       acc(names[i])
+      if opt and opt ~= true then acc('='..opt) end
    end
    acc ((']'):rep(npending))
    return  '('..table.concat(buffer)..')'
diff --git a/ldoc/parse.lua b/ldoc/parse.lua
index 176dc41..dded82c 100644
--- a/ldoc/parse.lua
+++ b/ldoc/parse.lua
@@ -36,7 +36,7 @@ local function parse_at_tags(text)
          modifiers  = { }
          for x in mod_string :gmatch "[^,]+" do
             local k, v = x :match "^([^=]+)=(.*)$"
-            if not k then k, v = x, x end
+            if not k then k, v = x, true end -- wuz x, x
             modifiers[k] = v
          end
       end
diff --git a/tests/styles/four.lua b/tests/styles/four.lua
index f2bcc31..91093c9 100644
--- a/tests/styles/four.lua
+++ b/tests/styles/four.lua
@@ -13,8 +13,8 @@
 -- you may document an indefinite number of extra arguments!
 -- @string name person's name
 -- @int age
--- @string[opt] calender optional calendar
--- @int[optchain] offset optional offset
+-- @string[opt='gregorian'] calender optional calendar
+-- @int[optchain=0] offset optional offset
 -- @treturn string
 function one (name,age,...)
 end