diff --git a/README.md b/README.md
index 3800d48..ce33d84 100644
--- a/README.md
+++ b/README.md
@@ -351,6 +351,10 @@ The documentation window's max width.
 
 The documentation window's max height.
 
+#### documentation.zindex (type: number)
+
+The documentation window's zindex.
+
 #### formatting.format (type: fun(entry: cmp.Entry, vim_item: vim.CompletedItem): vim.CompletedItem)
 
 A function to customize completion menu.
diff --git a/lua/cmp/types/cmp.lua b/lua/cmp/types/cmp.lua
index 49f9268..abed474 100644
--- a/lua/cmp/types/cmp.lua
+++ b/lua/cmp/types/cmp.lua
@@ -80,6 +80,7 @@ cmp.PreselectMode.None = 'none'
 ---@field public winhighlight string
 ---@field public maxwidth number|nil
 ---@field public maxheight number|nil
+---@field public zindex number|nil
 
 ---@class cmp.ConfirmationConfig
 ---@field public default_behavior cmp.ConfirmBehavior
diff --git a/lua/cmp/view/docs_view.lua b/lua/cmp/view/docs_view.lua
index 29555b1..36821ef 100644
--- a/lua/cmp/view/docs_view.lua
+++ b/lua/cmp/view/docs_view.lua
@@ -89,6 +89,7 @@ docs_view.open = function(self, e, view)
     row = view.row,
     col = col,
     border = documentation.border,
+    zindex = documentation.zindex,
   })
   if left and self.window:has_scrollbar() then
     self.window.style.col = self.window.style.col - 1