diff --git a/plugin/fzf.vim b/plugin/fzf.vim
index 7e3046a..b024c92 100644
--- a/plugin/fzf.vim
+++ b/plugin/fzf.vim
@@ -842,8 +842,12 @@ else
 endif
 
 function! s:popup(opts) abort
+  " Support ambiwidth == 'double'
+  let ambidouble = &ambiwidth == 'double' ? 2 : 1
+
   " Size and position
   let width = min([max([0, float2nr(&columns * a:opts.width)]), &columns])
+  let width += width % ambidouble
   let height = min([max([0, float2nr(&lines * a:opts.height)]), &lines - has('nvim')])
   let row = float2nr(get(a:opts, 'yoffset', 0.5) * (&lines - height))
   let col = float2nr(get(a:opts, 'xoffset', 0.5) * (&columns - width))
@@ -861,15 +865,15 @@ function! s:popup(opts) abort
   endif
 
   if style == 'horizontal'
-    let hor = repeat('─', width)
+    let hor = repeat('─', width / ambidouble)
     let mid = repeat(' ', width)
     let border = [hor] + repeat([mid], height - 2) + [hor]
     let margin = 0
   else
     let edges = style == 'sharp' ? ['┌', '┐', '└', '┘'] : ['╭', '╮', '╰', '╯']
-    let bar = repeat('─', width - 2)
+    let bar = repeat('─', width / ambidouble - 2)
     let top = edges[0] .. bar .. edges[1]
-    let mid = '│' .. repeat(' ', width - 2) .. '│'
+    let mid = '│' .. repeat(' ', width - 2 * ambidouble) .. '│'
     let bot = edges[2] .. bar .. edges[3]
     let border = [top] + repeat([mid], height - 2) + [bot]
     let margin = 2