diff --git a/lua/oil/init.lua b/lua/oil/init.lua
index f52f45d..736ae52 100644
--- a/lua/oil/init.lua
+++ b/lua/oil/init.lua
@@ -254,6 +254,7 @@ M.open_float = function(dir)
     border = config.float.border,
     zindex = 45,
   })
+  vim.w[winid].is_oil_win = true
   local winleave_autocmd
   winleave_autocmd = vim.api.nvim_create_autocmd("WinLeave", {
     desc = "Close floating oil window",
@@ -292,8 +293,7 @@ end
 
 ---Restore the buffer that was present when oil was opened
 M.close = function()
-  local util = require("oil.util")
-  if util.is_floating_win(0) then
+  if vim.w.is_oil_win then
     vim.api.nvim_win_close(0, true)
     return
   end
@@ -308,7 +308,7 @@ M.close = function()
 end
 
 ---Select the entry under the cursor
----@param opts table
+---@param opts nil|table
 ---    vertical boolean Open the buffer in a vertical split
 ---    horizontal boolean Open the buffer in a horizontal split
 ---    split "aboveleft"|"belowright"|"topleft"|"botright" Split modifier
@@ -397,7 +397,7 @@ M.select = function(opts)
         return
       end
     else
-      if util.is_floating_win() then
+      if vim.w.is_oil_win then
         vim.api.nvim_win_close(0, false)
       end
     end
diff --git a/tests/regression_spec.lua b/tests/regression_spec.lua
index 1e65f62..dd7651a 100644
--- a/tests/regression_spec.lua
+++ b/tests/regression_spec.lua
@@ -31,4 +31,20 @@ a.describe("regression tests", function()
     entry = oil.get_cursor_entry()
     assert.equals("README.md", entry and entry.name)
   end)
+
+  -- https://github.com/stevearc/oil.nvim/issues/64
+  a.it("doesn't close floating windows oil didn't open itself", function()
+    local winid = vim.api.nvim_open_win(vim.fn.bufadd("README.md"), true, {
+      relative = "editor",
+      row = 1,
+      col = 1,
+      width = 100,
+      height = 100,
+    })
+    oil.open()
+    a.util.sleep(10)
+    oil.close()
+    a.util.sleep(10)
+    assert.equals(winid, vim.api.nvim_get_current_win())
+  end)
 end)