diff --git a/README.md b/README.md
index 1c59fd6..80a2650 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # preview.nvim
 
-**Universal previewer for Neovim**
+**Universal document previewer for Neovim**
 
 An extensible framework for compiling and previewing _any_ documents (LaTeX,
 Typst, Markdown, etc.)—diagnostics included.
diff --git a/doc/preview.txt b/doc/preview.txt
index b4b74f5..383a8f5 100644
--- a/doc/preview.txt
+++ b/doc/preview.txt
@@ -68,10 +68,6 @@ Provider fields: ~
                                         receives a |preview.Context| and
                                         returns a string[].
 
-  {extra_args}       (string[]|function) Appended to {args} after evaluation.
-                                        Useful for adding flags to a preset
-                                        without replacing its defaults.
-
   {cwd}              (string|function)  Working directory. If a function,
                                         receives a |preview.Context|.
                                         Default: git root or file directory.
diff --git a/flake.nix b/flake.nix
index f6c279b..636f4d0 100644
--- a/flake.nix
+++ b/flake.nix
@@ -19,8 +19,7 @@
     {
       formatter = forEachSystem (pkgs: pkgs.nixfmt-tree);
 
-      devShells = forEachSystem (
-        pkgs:
+      devShells = forEachSystem (pkgs:
         let
           devTools = [
             (pkgs.luajit.withPackages (
@@ -51,7 +50,6 @@
               pkgs.mermaid-cli
             ];
           };
-        }
-      );
+        });
     };
 }
diff --git a/lua/preview/compiler.lua b/lua/preview/compiler.lua
index 3e8de12..a193ad2 100644
--- a/lua/preview/compiler.lua
+++ b/lua/preview/compiler.lua
@@ -309,9 +309,6 @@ function M.compile(bufnr, name, provider, ctx, opts)
   if provider.args then
     vim.list_extend(cmd, eval_list(provider.args, resolved_ctx))
   end
-  if provider.extra_args then
-    vim.list_extend(cmd, eval_list(provider.extra_args, resolved_ctx))
-  end
 
   log.dbg('compiling buffer %d with provider "%s": %s', bufnr, name, table.concat(cmd, ' '))
 
diff --git a/lua/preview/init.lua b/lua/preview/init.lua
index 489679f..7cb982b 100644
--- a/lua/preview/init.lua
+++ b/lua/preview/init.lua
@@ -2,7 +2,6 @@
 ---@field ft? string
 ---@field cmd string[]
 ---@field args? string[]|fun(ctx: preview.Context): string[]
----@field extra_args? string[]|fun(ctx: preview.Context): string[]
 ---@field cwd? string|fun(ctx: preview.Context): string
 ---@field env? table<string, string>
 ---@field output? string|fun(ctx: preview.Context): string
@@ -95,7 +94,6 @@ function M.setup(opts)
     vim.validate(prefix .. '.cmd', provider.cmd, 'table')
     vim.validate(prefix .. '.cmd[1]', provider.cmd[1], 'string')
     vim.validate(prefix .. '.args', provider.args, { 'table', 'function' }, true)
-    vim.validate(prefix .. '.extra_args', provider.extra_args, { 'table', 'function' }, true)
     vim.validate(prefix .. '.cwd', provider.cwd, { 'string', 'function' }, true)
     vim.validate(prefix .. '.output', provider.output, { 'string', 'function' }, true)
     vim.validate(prefix .. '.error_parser', provider.error_parser, 'function', true)
diff --git a/lua/preview/presets.lua b/lua/preview/presets.lua
index d4b03cc..1b5333e 100644
--- a/lua/preview/presets.lua
+++ b/lua/preview/presets.lua
@@ -115,24 +115,6 @@ local function parse_asciidoctor(output)
   return diagnostics
 end
 
----@param output string
----@return preview.Diagnostic[]
-local function parse_mermaid(output)
-  local lnum = output:match('Parse error on line (%d+)')
-  if not lnum then
-    return {}
-  end
-  local msg = output:match('(Expecting .+)') or 'parse error'
-  return {
-    {
-      lnum = tonumber(lnum) - 1,
-      col = 0,
-      message = msg,
-      severity = vim.diagnostic.severity.ERROR,
-    },
-  }
-end
-
 ---@type preview.ProviderConfig
 M.typst = {
   ft = 'typst',
@@ -331,7 +313,19 @@ M.mermaid = {
     return (ctx.file:gsub('%.mmd$', '.svg'))
   end,
   error_parser = function(output)
-    return parse_mermaid(output)
+    local diagnostics = {}
+    for line in output:gmatch('[^\r\n]+') do
+      local lnum = line:match('^%s*Parse error on line (%d+)')
+      if lnum then
+        table.insert(diagnostics, {
+          lnum = tonumber(lnum) - 1,
+          col = 0,
+          message = line,
+          severity = vim.diagnostic.severity.ERROR,
+        })
+      end
+    end
+    return diagnostics
   end,
   clean = function(ctx)
     return { 'rm', '-f', (ctx.file:gsub('%.mmd$', '.svg')) }