diff --git a/lua/codediff/ui/keymap_help.lua b/lua/codediff/ui/keymap_help.lua
index c6f29eab..c9cbf978 100644
--- a/lua/codediff/ui/keymap_help.lua
+++ b/lua/codediff/ui/keymap_help.lua
@@ -337,7 +337,7 @@ function M.toggle(tabpage)
     title_pos = "center",
   })
   vim.wo[win].cursorline = false
-  vim.wo[win].winhighlight = "NormalFloat:Normal"
+  vim.wo[win].winhighlight = "NormalFloat:NormalFloat"
 
   -- Track window in session for toggle
   if session then
diff --git a/tests/keymap/keymap_help_spec.lua b/tests/keymap/keymap_help_spec.lua
index 3afda4c4..25140162 100644
--- a/tests/keymap/keymap_help_spec.lua
+++ b/tests/keymap/keymap_help_spec.lua
@@ -258,6 +258,19 @@ describe("keymap help popup", function()
     cleanup()
   end)
 
+  it("uses NormalFloat for the help window body highlight", function()
+    local tabpage, cleanup = open_standalone()
+
+    keymap_help.toggle(tabpage)
+    local session = lifecycle.get_session(tabpage)
+    local win = session and session._help_win
+    assert.is_true(win ~= nil and vim.api.nvim_win_is_valid(win), "help window should open")
+    assert.are.same("NormalFloat:NormalFloat", vim.wo[win].winhighlight)
+    keymap_help.toggle(tabpage)
+
+    cleanup()
+  end)
+
   it("does not advertise a key disabled in config", function()
     local tabpage, cleanup = open_standalone({ keymaps = { view = { quit = false, toggle_compact = false } } })