diff --git a/lua/diffs/highlight.lua b/lua/diffs/highlight.lua
index 311a6f3..42c4868 100644
--- a/lua/diffs/highlight.lua
+++ b/lua/diffs/highlight.lua
@@ -3,6 +3,11 @@ local M = {}
 local dbg = require('diffs.log').dbg
 local diff = require('diffs.diff')
 
+local PRIORITY_CLEAR = 198
+local PRIORITY_SYNTAX = 199
+local PRIORITY_LINE_BG = 200
+local PRIORITY_CHAR_BG = 201
+
 ---@param bufnr integer
 ---@param ns integer
 ---@param hunk diffs.Hunk
@@ -38,7 +43,7 @@ local function highlight_text(bufnr, ns, hunk, col_offset, text, lang)
     local buf_sc = col_offset + sc
     local buf_ec = col_offset + ec
 
-    local priority = lang == 'diff' and (tonumber(metadata.priority) or 100) or 200
+    local priority = lang == 'diff' and (tonumber(metadata.priority) or 100) or PRIORITY_SYNTAX
 
     pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_sr, buf_sc, {
       end_row = buf_er,
@@ -58,16 +63,21 @@ end
 
 ---@param bufnr integer
 ---@param ns integer
----@param hunk diffs.Hunk
 ---@param code_lines string[]
----@param col_offset integer?
+---@param lang string
+---@param line_map table<integer, integer>
+---@param col_offset integer
+---@param covered_lines? table<integer, true>
 ---@return integer
-local function highlight_treesitter(bufnr, ns, hunk, code_lines, col_offset)
-  local lang = hunk.lang
-  if not lang then
-    return 0
-  end
-
+local function highlight_treesitter(
+  bufnr,
+  ns,
+  code_lines,
+  lang,
+  line_map,
+  col_offset,
+  covered_lines
+)
   local code = table.concat(code_lines, '\n')
   if code == '' then
     return 0
@@ -91,41 +101,31 @@ local function highlight_treesitter(bufnr, ns, hunk, code_lines, col_offset)
     return 0
   end
 
-  if hunk.header_context and hunk.header_context_col then
-    local header_line = hunk.start_line - 1
-    pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, header_line, hunk.header_context_col, {
-      end_col = hunk.header_context_col + #hunk.header_context,
-      hl_group = 'Normal',
-      priority = 199,
-    })
-    local header_extmarks =
-      highlight_text(bufnr, ns, hunk, hunk.header_context_col, hunk.header_context, lang)
-    if header_extmarks > 0 then
-      dbg('header %s:%d applied %d extmarks', hunk.filename, hunk.start_line, header_extmarks)
-    end
-  end
-
-  col_offset = col_offset or 1
-
   local extmark_count = 0
   for id, node, metadata in query:iter_captures(trees[1]:root(), code) do
     local capture_name = '@' .. query.captures[id] .. '.' .. lang
     local sr, sc, er, ec = node:range()
 
-    local buf_sr = hunk.start_line + sr
-    local buf_er = hunk.start_line + er
-    local buf_sc = sc + col_offset
-    local buf_ec = ec + col_offset
+    local buf_sr = line_map[sr]
+    if buf_sr then
+      local buf_er = line_map[er] or buf_sr
 
-    local priority = lang == 'diff' and (tonumber(metadata.priority) or 100) or 200
+      local buf_sc = sc + col_offset
+      local buf_ec = ec + col_offset
 
-    pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_sr, buf_sc, {
-      end_row = buf_er,
-      end_col = buf_ec,
-      hl_group = capture_name,
-      priority = priority,
-    })
-    extmark_count = extmark_count + 1
+      local priority = lang == 'diff' and (tonumber(metadata.priority) or 100) or PRIORITY_SYNTAX
+
+      pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_sr, buf_sc, {
+        end_row = buf_er,
+        end_col = buf_ec,
+        hl_group = capture_name,
+        priority = priority,
+      })
+      extmark_count = extmark_count + 1
+      if covered_lines then
+        covered_lines[buf_sr] = true
+      end
+    end
   end
 
   return extmark_count
@@ -176,8 +176,9 @@ end
 ---@param ns integer
 ---@param hunk diffs.Hunk
 ---@param code_lines string[]
+---@param covered_lines? table<integer, true>
 ---@return integer
-local function highlight_vim_syntax(bufnr, ns, hunk, code_lines)
+local function highlight_vim_syntax(bufnr, ns, hunk, code_lines, covered_lines)
   local ft = hunk.ft
   if not ft then
     return 0
@@ -219,9 +220,12 @@ local function highlight_vim_syntax(bufnr, ns, hunk, code_lines)
     pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_line, span.col_start, {
       end_col = span.col_end,
       hl_group = span.hl_name,
-      priority = 200,
+      priority = PRIORITY_SYNTAX,
     })
     extmark_count = extmark_count + 1
+    if covered_lines then
+      covered_lines[buf_line] = true
+    end
   end
 
   return extmark_count
@@ -248,21 +252,63 @@ function M.highlight_hunk(bufnr, ns, hunk, opts)
     use_vim = false
   end
 
-  local apply_syntax = use_ts or use_vim
-
-  ---@type string[]
-  local code_lines = {}
-  if apply_syntax then
-    for _, line in ipairs(hunk.lines) do
-      table.insert(code_lines, line:sub(2))
-    end
-  end
+  ---@type table<integer, true>
+  local covered_lines = {}
 
   local extmark_count = 0
   if use_ts then
-    extmark_count = highlight_treesitter(bufnr, ns, hunk, code_lines)
+    ---@type string[]
+    local new_code = {}
+    ---@type table<integer, integer>
+    local new_map = {}
+    ---@type string[]
+    local old_code = {}
+    ---@type table<integer, integer>
+    local old_map = {}
+
+    for i, line in ipairs(hunk.lines) do
+      local prefix = line:sub(1, 1)
+      local stripped = line:sub(2)
+      local buf_line = hunk.start_line + i - 1
+
+      if prefix == '+' then
+        new_map[#new_code] = buf_line
+        table.insert(new_code, stripped)
+      elseif prefix == '-' then
+        old_map[#old_code] = buf_line
+        table.insert(old_code, stripped)
+      else
+        new_map[#new_code] = buf_line
+        table.insert(new_code, stripped)
+        table.insert(old_code, stripped)
+      end
+    end
+
+    extmark_count = highlight_treesitter(bufnr, ns, new_code, hunk.lang, new_map, 1, covered_lines)
+    extmark_count = extmark_count
+      + highlight_treesitter(bufnr, ns, old_code, hunk.lang, old_map, 1, covered_lines)
+
+    if hunk.header_context and hunk.header_context_col then
+      local header_line = hunk.start_line - 1
+      pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, header_line, hunk.header_context_col, {
+        end_col = hunk.header_context_col + #hunk.header_context,
+        hl_group = 'DiffsClear',
+        priority = PRIORITY_CLEAR,
+      })
+      local header_extmarks =
+        highlight_text(bufnr, ns, hunk, hunk.header_context_col, hunk.header_context, hunk.lang)
+      if header_extmarks > 0 then
+        dbg('header %s:%d applied %d extmarks', hunk.filename, hunk.start_line, header_extmarks)
+      end
+      extmark_count = extmark_count + header_extmarks
+    end
   elseif use_vim then
-    extmark_count = highlight_vim_syntax(bufnr, ns, hunk, code_lines)
+    ---@type string[]
+    local code_lines = {}
+    for _, line in ipairs(hunk.lines) do
+      table.insert(code_lines, line:sub(2))
+    end
+    extmark_count = highlight_vim_syntax(bufnr, ns, hunk, code_lines, covered_lines)
   end
 
   if
@@ -271,18 +317,15 @@ function M.highlight_hunk(bufnr, ns, hunk, opts)
     and #hunk.header_lines > 0
     and opts.highlights.treesitter.enabled
   then
+    ---@type table<integer, integer>
+    local header_map = {}
+    for i = 0, #hunk.header_lines - 1 do
+      header_map[i] = hunk.header_start_line - 1 + i
+    end
     extmark_count = extmark_count
-      + highlight_treesitter(bufnr, ns, {
-        filename = hunk.filename,
-        start_line = hunk.header_start_line - 1,
-        lang = 'diff',
-        lines = hunk.header_lines,
-        header_lines = {},
-      }, hunk.header_lines, 0)
+      + highlight_treesitter(bufnr, ns, hunk.header_lines, 'diff', header_map, 0)
   end
 
-  local syntax_applied = extmark_count > 0
-
   ---@type diffs.IntraChanges?
   local intra = nil
   local intra_cfg = opts.highlights.intra
@@ -334,11 +377,11 @@ function M.highlight_hunk(bufnr, ns, hunk, opts)
       })
     end
 
-    if line_len > 1 and syntax_applied then
+    if line_len > 1 and covered_lines[buf_line] then
       pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_line, 1, {
         end_col = line_len,
-        hl_group = 'Normal',
-        priority = 198,
+        hl_group = 'DiffsClear',
+        priority = PRIORITY_CLEAR,
       })
     end
 
@@ -348,7 +391,7 @@ function M.highlight_hunk(bufnr, ns, hunk, opts)
         hl_group = line_hl,
         hl_eol = true,
         number_hl_group = opts.highlights.gutter and number_hl or nil,
-        priority = 199,
+        priority = PRIORITY_LINE_BG,
       })
     end
 
@@ -367,7 +410,7 @@ function M.highlight_hunk(bufnr, ns, hunk, opts)
         local ok, err = pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_line, span.col_start, {
           end_col = span.col_end,
           hl_group = char_hl,
-          priority = 201,
+          priority = PRIORITY_CHAR_BG,
         })
         if not ok then
           dbg('char extmark FAILED: %s', err)
diff --git a/lua/diffs/init.lua b/lua/diffs/init.lua
index ca8aa1a..a5dfcf0 100644
--- a/lua/diffs/init.lua
+++ b/lua/diffs/init.lua
@@ -186,6 +186,7 @@ local function compute_highlight_groups()
   local blended_add_text = blend_color(add_fg, bg, 0.7)
   local blended_del_text = blend_color(del_fg, bg, 0.7)
 
+  vim.api.nvim_set_hl(0, 'DiffsClear', { default = true, fg = normal.fg or 0xc0c0c0 })
   vim.api.nvim_set_hl(0, 'DiffsAdd', { default = true, bg = blended_add })
   vim.api.nvim_set_hl(0, 'DiffsDelete', { default = true, bg = blended_del })
   vim.api.nvim_set_hl(0, 'DiffsAddNr', { default = true, fg = add_fg, bg = blended_add })
diff --git a/spec/highlight_spec.lua b/spec/highlight_spec.lua
index bb125fd..1257523 100644
--- a/spec/highlight_spec.lua
+++ b/spec/highlight_spec.lua
@@ -7,8 +7,10 @@ describe('highlight', function()
 
     before_each(function()
       ns = vim.api.nvim_create_namespace('diffs_test')
+      local normal = vim.api.nvim_get_hl(0, { name = 'Normal' })
       local diff_add = vim.api.nvim_get_hl(0, { name = 'DiffAdd' })
       local diff_delete = vim.api.nvim_get_hl(0, { name = 'DiffDelete' })
+      vim.api.nvim_set_hl(0, 'DiffsClear', { fg = normal.fg or 0xc0c0c0 })
       vim.api.nvim_set_hl(0, 'DiffsAdd', { bg = diff_add.bg })
       vim.api.nvim_set_hl(0, 'DiffsDelete', { bg = diff_delete.bg })
     end)
@@ -82,7 +84,7 @@ describe('highlight', function()
       delete_buffer(bufnr)
     end)
 
-    it('applies Normal extmarks to clear diff colors', function()
+    it('applies DiffsClear extmarks to clear diff colors', function()
       local bufnr = create_buffer({
         '@@ -1,1 +1,2 @@',
         ' local x = 1',
@@ -99,14 +101,46 @@ describe('highlight', function()
       highlight.highlight_hunk(bufnr, ns, hunk, default_opts())
 
       local extmarks = get_extmarks(bufnr)
-      local has_normal = false
+      local has_clear = false
       for _, mark in ipairs(extmarks) do
-        if mark[4] and mark[4].hl_group == 'Normal' then
-          has_normal = true
+        if mark[4] and mark[4].hl_group == 'DiffsClear' then
+          has_clear = true
           break
         end
       end
-      assert.is_true(has_normal)
+      assert.is_true(has_clear)
+      delete_buffer(bufnr)
+    end)
+
+    it('produces treesitter captures on all lines with split parsing', function()
+      local bufnr = create_buffer({
+        '@@ -1,3 +1,3 @@',
+        ' local x = 1',
+        '-local y = 2',
+        '+local y = 3',
+        ' return x',
+      })
+
+      local hunk = {
+        filename = 'test.lua',
+        lang = 'lua',
+        start_line = 1,
+        lines = { ' local x = 1', '-local y = 2', '+local y = 3', ' return x' },
+      }
+
+      highlight.highlight_hunk(bufnr, ns, hunk, default_opts())
+
+      local extmarks = get_extmarks(bufnr)
+      local lines_with_ts = {}
+      for _, mark in ipairs(extmarks) do
+        if mark[4] and mark[4].hl_group and mark[4].hl_group:match('^@.*%.lua$') then
+          lines_with_ts[mark[2]] = true
+        end
+      end
+      assert.is_true(lines_with_ts[1] ~= nil)
+      assert.is_true(lines_with_ts[2] ~= nil)
+      assert.is_true(lines_with_ts[3] ~= nil)
+      assert.is_true(lines_with_ts[4] ~= nil)
       delete_buffer(bufnr)
     end)
 
@@ -576,7 +610,7 @@ describe('highlight', function()
       local extmarks = get_extmarks(bufnr)
       local has_syntax_hl = false
       for _, mark in ipairs(extmarks) do
-        if mark[4] and mark[4].hl_group and mark[4].hl_group ~= 'Normal' then
+        if mark[4] and mark[4].hl_group and mark[4].hl_group ~= 'DiffsClear' then
           has_syntax_hl = true
           break
         end
@@ -610,7 +644,7 @@ describe('highlight', function()
       local extmarks = get_extmarks(bufnr)
       local has_syntax_hl = false
       for _, mark in ipairs(extmarks) do
-        if mark[4] and mark[4].hl_group and mark[4].hl_group ~= 'Normal' then
+        if mark[4] and mark[4].hl_group and mark[4].hl_group ~= 'DiffsClear' then
           has_syntax_hl = true
           break
         end
@@ -682,7 +716,7 @@ describe('highlight', function()
       delete_buffer(bufnr)
     end)
 
-    it('applies Normal blanking for vim fallback hunks', function()
+    it('applies DiffsClear blanking for vim fallback hunks', function()
       local orig_synID = vim.fn.synID
       local orig_synIDtrans = vim.fn.synIDtrans
       local orig_synIDattr = vim.fn.synIDattr
@@ -722,14 +756,14 @@ describe('highlight', function()
       vim.fn.synIDattr = orig_synIDattr
 
       local extmarks = get_extmarks(bufnr)
-      local has_normal = false
+      local has_clear = false
       for _, mark in ipairs(extmarks) do
-        if mark[4] and mark[4].hl_group == 'Normal' then
-          has_normal = true
+        if mark[4] and mark[4].hl_group == 'DiffsClear' then
+          has_clear = true
           break
         end
       end
-      assert.is_true(has_normal)
+      assert.is_true(has_clear)
       delete_buffer(bufnr)
     end)
 
@@ -765,7 +799,7 @@ describe('highlight', function()
       delete_buffer(bufnr)
     end)
 
-    it('line bg priority > Normal priority', function()
+    it('line bg priority > DiffsClear priority', function()
       local bufnr = create_buffer({
         '@@ -1,2 +1,1 @@',
         '-local x = 1',
@@ -787,20 +821,20 @@ describe('highlight', function()
       )
 
       local extmarks = get_extmarks(bufnr)
-      local normal_priority = nil
+      local clear_priority = nil
       local line_bg_priority = nil
       for _, mark in ipairs(extmarks) do
         local d = mark[4]
-        if d and d.hl_group == 'Normal' then
-          normal_priority = d.priority
+        if d and d.hl_group == 'DiffsClear' then
+          clear_priority = d.priority
         end
         if d and (d.hl_group == 'DiffsAdd' or d.hl_group == 'DiffsDelete') then
           line_bg_priority = d.priority
         end
       end
-      assert.is_not_nil(normal_priority)
+      assert.is_not_nil(clear_priority)
       assert.is_not_nil(line_bg_priority)
-      assert.is_true(line_bg_priority > normal_priority)
+      assert.is_true(line_bg_priority > clear_priority)
       delete_buffer(bufnr)
     end)
 
@@ -960,7 +994,7 @@ describe('highlight', function()
       delete_buffer(bufnr)
     end)
 
-    it('enforces priority order: Normal < line bg < syntax < char bg', function()
+    it('enforces priority order: DiffsClear < syntax < line bg < char bg', function()
       vim.api.nvim_set_hl(0, 'DiffsAddText', { bg = 0x00FF00 })
       vim.api.nvim_set_hl(0, 'DiffsDeleteText', { bg = 0xFF0000 })
 
@@ -990,12 +1024,12 @@ describe('highlight', function()
       )
 
       local extmarks = get_extmarks(bufnr)
-      local priorities = { normal = {}, line_bg = {}, syntax = {}, char_bg = {} }
+      local priorities = { clear = {}, line_bg = {}, syntax = {}, char_bg = {} }
       for _, mark in ipairs(extmarks) do
         local d = mark[4]
         if d then
-          if d.hl_group == 'Normal' then
-            table.insert(priorities.normal, d.priority)
+          if d.hl_group == 'DiffsClear' then
+            table.insert(priorities.clear, d.priority)
           elseif d.hl_group == 'DiffsAdd' or d.hl_group == 'DiffsDelete' then
             table.insert(priorities.line_bg, d.priority)
           elseif d.hl_group == 'DiffsAddText' or d.hl_group == 'DiffsDeleteText' then
@@ -1006,19 +1040,19 @@ describe('highlight', function()
         end
       end
 
-      assert.is_true(#priorities.normal > 0)
+      assert.is_true(#priorities.clear > 0)
       assert.is_true(#priorities.line_bg > 0)
       assert.is_true(#priorities.syntax > 0)
       assert.is_true(#priorities.char_bg > 0)
 
-      local max_normal = math.max(unpack(priorities.normal))
+      local max_clear = math.max(unpack(priorities.clear))
       local min_line_bg = math.min(unpack(priorities.line_bg))
       local min_syntax = math.min(unpack(priorities.syntax))
       local min_char_bg = math.min(unpack(priorities.char_bg))
 
-      assert.is_true(max_normal < min_line_bg)
-      assert.is_true(min_line_bg < min_syntax)
-      assert.is_true(min_syntax < min_char_bg)
+      assert.is_true(max_clear < min_syntax)
+      assert.is_true(min_syntax < min_line_bg)
+      assert.is_true(min_line_bg < min_char_bg)
       delete_buffer(bufnr)
     end)
   end)
@@ -1214,7 +1248,7 @@ describe('highlight', function()
       }
     end
 
-    it('uses priority 200 for code languages', function()
+    it('uses priority 199 for code languages', function()
       local bufnr = create_buffer({
         '@@ -1,1 +1,2 @@',
         ' local x = 1',
@@ -1231,16 +1265,16 @@ describe('highlight', function()
       highlight.highlight_hunk(bufnr, ns, hunk, default_opts())
 
       local extmarks = get_extmarks(bufnr)
-      local has_priority_200 = false
+      local has_priority_199 = false
       for _, mark in ipairs(extmarks) do
         if mark[4] and mark[4].hl_group and mark[4].hl_group:match('^@.*%.lua$') then
-          if mark[4].priority == 200 then
-            has_priority_200 = true
+          if mark[4].priority == 199 then
+            has_priority_199 = true
             break
           end
         end
       end
-      assert.is_true(has_priority_200)
+      assert.is_true(has_priority_199)
       delete_buffer(bufnr)
     end)
 
@@ -1278,7 +1312,7 @@ describe('highlight', function()
       end
       assert.is_true(#diff_extmark_priorities > 0)
       for _, priority in ipairs(diff_extmark_priorities) do
-        assert.is_true(priority < 200)
+        assert.is_true(priority < 199)
       end
       delete_buffer(bufnr)
     end)