diff --git a/src/nvim/window.c b/src/nvim/window.c
index aea60fe24c..acdc40dc74 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -737,6 +737,37 @@ void win_config_float(win_T *wp, FloatConfig fconfig)
     redraw_later(wp, NOT_VALID);
   }
 
+  // compute initial position
+  if (wp->w_float_config.relative == kFloatRelativeWindow) {
+    int row = wp->w_float_config.row;
+    int col = wp->w_float_config.col;
+    Error dummy = ERROR_INIT;
+    win_T *parent = find_window_by_handle(wp->w_float_config.window, &dummy);
+    if (parent) {
+      row += parent->w_winrow;
+      col += parent->w_wincol;
+      ScreenGrid *grid = &parent->w_grid;
+      int row_off = 0, col_off = 0;
+      screen_adjust_grid(&grid, &row_off, &col_off);
+      row += row_off;
+      col += col_off;
+    }
+    api_clear_error(&dummy);
+    if (wp->w_float_config.bufpos.lnum >= 0) {
+      pos_T pos = { wp->w_float_config.bufpos.lnum + 1,
+        wp->w_float_config.bufpos.col, 0 };
+      int trow, tcol, tcolc, tcole;
+      textpos2screenpos(wp, &pos, &trow, &tcol, &tcolc, &tcole, true);
+      row += trow - 1;
+      col += tcol - 1;
+    }
+    wp->w_winrow = row;
+    wp->w_wincol = col;
+  } else {
+    wp->w_winrow = fconfig.row;
+    wp->w_wincol = fconfig.col;
+  }
+
   // changing border style while keeping border only requires redrawing border
   if (fconfig.border) {
     wp->w_redr_border = true;
@@ -770,7 +801,6 @@ int win_fdccol_count(win_T *wp)
   }
 }
 
-
 void ui_ext_win_position(win_T *wp)
 {
   if (!wp->w_floating) {
@@ -817,6 +847,8 @@ void ui_ext_win_position(win_T *wp)
 
       int comp_row = (int)row - (south ? wp->w_height : 0);
       int comp_col = (int)col - (east ? wp->w_width : 0);
+      comp_row += grid->comp_row;
+      comp_col += grid->comp_col;
       comp_row = MAX(MIN(comp_row, Rows-wp->w_height_outer-1), 0);
       comp_col = MAX(MIN(comp_col, Columns-wp->w_width_outer), 0);
       wp->w_winrow = comp_row;
diff --git a/test/functional/ui/float_spec.lua b/test/functional/ui/float_spec.lua
index f3b840da21..16feb3e56b 100644
--- a/test/functional/ui/float_spec.lua
+++ b/test/functional/ui/float_spec.lua
@@ -152,6 +152,132 @@ describe('float window', function()
     eq(10, width)
   end)
 
+  it('opened with correct position', function()
+    local pos = exec_lua([[
+      local bufnr = vim.api.nvim_create_buf(false, true)
+
+      local opts = {
+        width = 10,
+        height = 10,
+        col = 7,
+        row = 9,
+        relative = 'editor',
+        style = 'minimal'
+      }
+
+      local win_id = vim.api.nvim_open_win(bufnr, false, opts)
+
+      return vim.api.nvim_win_get_position(win_id)
+    ]])
+
+    eq(9, pos[1])
+    eq(7, pos[2])
+  end)
+
+  it('opened with correct position relative to the cursor', function()
+    local pos = exec_lua([[
+      local bufnr = vim.api.nvim_create_buf(false, true)
+
+      local opts = {
+        width = 10,
+        height = 10,
+        col = 7,
+        row = 9,
+        relative = 'cursor',
+        style = 'minimal'
+      }
+
+      local win_id = vim.api.nvim_open_win(bufnr, false, opts)
+
+      return vim.api.nvim_win_get_position(win_id)
+    ]])
+
+    eq(9, pos[1])
+    eq(7, pos[2])
+  end)
+
+  it('opened with correct position relative to another window', function()
+    local pos = exec_lua([[
+      local bufnr = vim.api.nvim_create_buf(false, true)
+
+      local par_opts = {
+        width = 50,
+        height = 50,
+        col = 7,
+        row = 9,
+        relative = 'editor',
+        style = 'minimal'
+      }
+
+      local par_win_id = vim.api.nvim_open_win(bufnr, false, par_opts)
+
+      local opts = {
+        width = 10,
+        height = 10,
+        col = 7,
+        row = 9,
+        relative = 'win',
+        style = 'minimal',
+        win = par_win_id
+      }
+
+      local win_id = vim.api.nvim_open_win(bufnr, false, opts)
+
+      return vim.api.nvim_win_get_position(win_id)
+    ]])
+
+    eq(18, pos[1])
+    eq(14, pos[2])
+  end)
+
+
+  it('opened with correct position relative to another relative window', function()
+    local pos = exec_lua([[
+      local bufnr = vim.api.nvim_create_buf(false, true)
+
+      local root_opts = {
+        width = 50,
+        height = 50,
+        col = 7,
+        row = 9,
+        relative = 'editor',
+        style = 'minimal'
+      }
+
+      local root_win_id = vim.api.nvim_open_win(bufnr, false, root_opts)
+
+      local par_opts = {
+        width = 20,
+        height = 20,
+        col = 2,
+        row = 3,
+        relative = 'win',
+        win = root_win_id,
+        style = 'minimal'
+      }
+
+      local par_win_id = vim.api.nvim_open_win(bufnr, false, par_opts)
+
+      local opts = {
+        width = 10,
+        height = 10,
+        col = 3,
+        row = 2,
+        relative = 'win',
+        win = par_win_id,
+        style = 'minimal'
+      }
+
+      local win_id = vim.api.nvim_open_win(bufnr, false, opts)
+
+      return vim.api.nvim_win_get_position(win_id)
+    ]])
+
+    eq(14, pos[1])
+    eq(12, pos[2])
+  end)
+
+
   local function with_ext_multigrid(multigrid)
     local screen
     before_each(function()