diff --git a/lua/nvim_lsp/omnisharp.lua b/lua/nvim_lsp/omnisharp.lua
new file mode 100644
index 0000000000..1aaaf83a70
--- /dev/null
+++ b/lua/nvim_lsp/omnisharp.lua
@@ -0,0 +1,84 @@
+local configs = require 'nvim_lsp/configs'
+local util = require 'nvim_lsp/util'
+local server_name = 'omnisharp'
+local bin_name = 'run'
+
+local function make_installer()
+  local install_dir = util.path.join{util.base_install_dir, server_name}
+
+  local url = 'linux-x64'
+
+  if vim.fn.has('win32') == 1 then
+    url = 'win-x64'
+    bin_name = 'Omnisharp.exe'
+  elseif vim.fn.has('mac') == 1 then
+    url = 'osx'
+  end
+  local bin_path = util.path.join{install_dir, bin_name}
+
+  local download_target = util.path.join{install_dir, string.format("omnisharp-%s.zip", url)}
+  local extract_cmd = string.format("unzip '%s' -d '%s'", download_target, install_dir)
+  local download_cmd = string.format('curl -fLo "%s" --create-dirs "https://github.com/OmniSharp/omnisharp-roslyn/releases/latest/download/omnisharp-%s.zip"', download_target, url)
+  local make_executable_cmd = string.format("chmod u+x '%s'", bin_path)
+
+  local X = {}
+  function X.install()
+    local install_info = X.info()
+    if install_info.is_installed then
+      print(server_name, "is already installed")
+      return
+    end
+    if not (util.has_bins("curl")) then
+      error('Need "curl" to install this.')
+      return
+    end
+    vim.fn.mkdir(install_dir, 'p')
+    vim.fn.system(download_cmd)
+    vim.fn.system(extract_cmd)
+    vim.fn.system(make_executable_cmd)
+  end
+  function X.info()
+    return {
+      is_installed = util.path.exists(bin_path);
+      install_dir = install_dir;
+      cmd = { bin_path, "--languageserver" };
+    }
+  end
+  function X.configure(config)
+    local install_info = X.info()
+    if install_info.is_installed then
+      config.cmd = install_info.cmd
+    end
+  end
+  return X
+end
+
+local installer = make_installer()
+
+configs[server_name] = {
+  default_config = {
+    cmd = installer.info().cmd;
+    filetypes = {"cs", "vb"};
+    root_dir = util.root_pattern("*.csproj", "*.sln");
+    on_new_config = function(config)
+      installer.configure(config)
+    end;
+    init_options = {
+    };
+  };
+  -- on_new_config = function(new_config) end;
+  -- on_attach = function(client, bufnr) end;
+  docs = {
+    description = [[
+https://github.com/omnisharp/omnisharp-roslyn
+OmniSharp server based on Roslyn workspaces
+]];
+    default_config = {
+      root_dir = [[root_pattern(".csproj", ".sln", ".git")]];
+    };
+  };
+}
+
+configs[server_name].install = installer.install
+configs[server_name].install_info = installer.info
+-- vim:et ts=2 sw=2
diff --git a/lua/nvim_lsp/util.lua b/lua/nvim_lsp/util.lua
index 83e3632194..c125c33f02 100644
--- a/lua/nvim_lsp/util.lua
+++ b/lua/nvim_lsp/util.lua
@@ -290,7 +290,7 @@ function M.root_pattern(...)
   local patterns = vim.tbl_flatten {...}
   local function matcher(path)
     for _, pattern in ipairs(patterns) do
-      if M.path.exists(M.path.join(path, pattern)) then
+      if M.path.exists(vim.fn.glob(M.path.join(path, pattern))) then
         return path
       end
     end