diff --git a/flake.nix b/flake.nix
index 2221bdf..7f36402 100644
--- a/flake.nix
+++ b/flake.nix
@@ -36,7 +36,7 @@
               trap 'rm -rf "$tmpdir"' EXIT
               printf '#!/bin/sh\nexec "%s" --cmd "set rtp+=${ts-plugin}/runtime" --cmd "set rtp+=${diff-grammar}" "$@"\n' "$nvim_bin" > "$tmpdir/nvim"
               chmod +x "$tmpdir/nvim"
-              PATH="$tmpdir:$PATH" exec ${luaEnv}/bin/busted "$@"
+              NVIM_APPNAME=nvim-tmp PATH="$tmpdir:$PATH" exec ${luaEnv}/bin/busted "$@"
             '';
           in
           pkgs.mkShell {
diff --git a/lua/diffs/highlight.lua b/lua/diffs/highlight.lua
index ed9329b..c11d440 100644
--- a/lua/diffs/highlight.lua
+++ b/lua/diffs/highlight.lua
@@ -636,11 +636,19 @@ function M.highlight_hunk(bufnr, ns, hunk, opts)
       end
 
       if opts.highlights.background and is_diff_line then
+        -- NOTE: must use separate extmark here https://github.com/neovim/neovim/issues/31151
         pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_line, 0, {
-          line_hl_group = line_hl,
-          number_hl_group = opts.highlights.gutter and number_hl or nil,
+          end_row = buf_line + 1,
+          hl_group = line_hl,
+          hl_eol = true,
           priority = p.line_bg,
         })
+        if opts.highlights.gutter then
+          pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_line, 0, {
+            number_hl_group = number_hl,
+            priority = p.line_bg,
+          })
+        end
       end
 
       if is_marker and line_len > pw then