diff --git a/neovim/README.md b/neovim/README.md
index 57f4af4..aa6f6e4 100644
--- a/neovim/README.md
+++ b/neovim/README.md
@@ -37,6 +37,12 @@ machine gets the same set.
 > nvim-web-devicons needs a Nerd Font in the terminal or the icons render as
 > tofu. `brew.sh` installs one for ghostty.
 
+> [!NOTE]
+> codediff.nvim does its diffing in C. It downloads a prebuilt library into its
+> own plugin directory on first use — so the first `:CodeDiff` on a new machine
+> needs network, and the binary is not covered by the lock file. `:CodeDiff
+> install!` forces a re-download if it ever goes missing or stale.
+
 ## Defaults worth knowing
 
 - **The colorscheme is catppuccin**, `flavour = 'auto'`: latte on a light
diff --git a/neovim/config/plugins/diffview.lua b/neovim/config/plugins/codediff.lua
similarity index 53%
rename from neovim/config/plugins/diffview.lua
rename to neovim/config/plugins/codediff.lua
index 0f7befd..80775fe 100644
--- a/neovim/config/plugins/diffview.lua
+++ b/neovim/config/plugins/codediff.lua
@@ -1,15 +1,20 @@
-vim.pack.add({ 'https://github.com/sindrets/diffview.nvim' })
+vim.pack.add({ 'https://github.com/esmuellert/codediff.nvim' })
 
-require('diffview').setup()
+require('codediff').setup({
+  keymaps = {
+    -- q closes the diff tab from inside it; <leader>gc is here too so the
+    -- same key that opened things from the g/diff group also shuts them.
+    view = { quit = { 'q', '<leader>gc' } },
+  },
+})
 
 local function map(lhs, rhs, desc)
   vim.keymap.set('n', lhs, rhs, { desc = desc })
 end
 
-map('<leader>gd', '<Cmd>DiffviewOpen<CR>', 'Diff against index')
-map('<leader>gc', '<Cmd>DiffviewClose<CR>', 'Close diff view')
-map('<leader>gh', '<Cmd>DiffviewFileHistory %<CR>', 'File history')
-map('<leader>gH', '<Cmd>DiffviewFileHistory<CR>', 'Branch history')
+map('<leader>gd', '<Cmd>CodeDiff<CR>', 'Diff working tree')
+map('<leader>gh', '<Cmd>CodeDiff history %<CR>', 'File history')
+map('<leader>gH', '<Cmd>CodeDiff history<CR>', 'Branch history')
 
 -- The base branch name varies per repo (main, master, develop, ...), so ask
 -- the first remote's HEAD what it is rather than hardcoding one.
@@ -28,7 +33,9 @@ end
 map('<leader>gm', function()
   vim.ui.input({ prompt = 'Diff against: ', default = default_branch() }, function(rev)
     if rev and rev ~= '' then
-      vim.cmd('DiffviewOpen ' .. rev .. '...HEAD')
+      -- rev...HEAD is merge-base semantics: what this branch added, not what
+      -- the base branch has moved on to since.
+      vim.cmd('CodeDiff ' .. rev .. '...HEAD')
     end
   end)
 end, 'Diff against branch')
diff --git a/neovim/config/plugins/init.lua b/neovim/config/plugins/init.lua
index 7046983..ea9535b 100644
--- a/neovim/config/plugins/init.lua
+++ b/neovim/config/plugins/init.lua
@@ -1,6 +1,6 @@
 -- The colorscheme goes first so everything after it is drawn with it applied
 require('config.plugins.catppuccin')
-require('config.plugins.diffview')
+require('config.plugins.codediff')
 require('config.plugins.fzf-lua')
 require('config.plugins.gitsigns')
 require('config.plugins.nvim-tree')
diff --git a/neovim/nvim-pack-lock.json b/neovim/nvim-pack-lock.json
index c80ef95..9508372 100644
--- a/neovim/nvim-pack-lock.json
+++ b/neovim/nvim-pack-lock.json
@@ -4,9 +4,9 @@
       "rev": "edefef779ab08ce1a4a404713e3012b0d202bd35",
       "src": "https://github.com/catppuccin/nvim"
     },
-    "diffview.nvim": {
-      "rev": "4516612fe98ff56ae0415a259ff6361a89419b0a",
-      "src": "https://github.com/sindrets/diffview.nvim"
+    "codediff.nvim": {
+      "rev": "e08a35a56a52c290398ebfaec33c34cfcf2d0f3c",
+      "src": "https://github.com/esmuellert/codediff.nvim"
     },
     "fzf-lua": {
       "rev": "8671012a7b2a1648595952c655039d51fb301c14",