diff --git a/lips/Dumper.lua b/lips/Dumper.lua
index 5a41c45..9cb1837 100644
--- a/lips/Dumper.lua
+++ b/lips/Dumper.lua
@@ -127,13 +127,13 @@ function Dumper:add_directive(fn, line, name, a, b)
         end
         local temp = self.pos + align - 1
         t.skip = temp - (temp % align) - self.pos
-        t.fill = t.fill or 0
+        t.fill = b and b % 0x100 or 0
         insert(self.commands, t)
         self:advance(t.skip)
     elseif name == 'SKIP' then
         t.kind = 'ahead'
         t.skip = a
-        t.fill = b
+        t.fill = b and b % 0x100 or nil
         insert(self.commands, t)
         self:advance(t.skip)
     else
diff --git a/lips/Parser.lua b/lips/Parser.lua
index bb2ce09..ff0a774 100644
--- a/lips/Parser.lua
+++ b/lips/Parser.lua
@@ -23,7 +23,6 @@ function Parser:directive()
     local function add(...)
         self.dumper:add_directive(self.fn, self.line, ...)
     end
-    -- FIXME: some of these directives allow byte values greater than 255
     if name == 'ORG' then
         add(name, self:number().tok)
     elseif name == 'ALIGN' or name == 'SKIP' then