diff --git a/test/shell.d/theme-neovim-colorscheme-test.sh b/test/shell.d/theme-neovim-colorscheme-test.sh
new file mode 100755
index 00000000..a1c4a8a8
--- /dev/null
+++ b/test/shell.d/theme-neovim-colorscheme-test.sh
@@ -0,0 +1,15 @@
+#!/bin/bash
+
+source "$(dirname "${BASH_SOURCE[0]}")/base-test.sh"
+
+# The catppuccin-nvim colorscheme name only exists in newer plugin checkouts
+# (added upstream in March 2026); catppuccin-mocha loads on old and new ones
+# alike, so the stock theme uses the flavour name (#12721).
+if matches=$(grep -rn 'catppuccin-nvim' "$ROOT/themes/"); then
+  fail "stock themes avoid the newer-only catppuccin colorscheme name" "$matches"
+fi
+pass "stock themes avoid the newer-only catppuccin colorscheme name"
+
+grep -Fq 'colorscheme = "catppuccin-mocha"' "$ROOT/themes/catppuccin/neovim.lua" ||
+  fail "catppuccin theme uses its flavour colorscheme"
+pass "catppuccin theme uses its flavour colorscheme"
diff --git a/themes/catppuccin/neovim.lua b/themes/catppuccin/neovim.lua
index f0d503f9..930d8644 100644
--- a/themes/catppuccin/neovim.lua
+++ b/themes/catppuccin/neovim.lua
@@ -7,7 +7,7 @@ return {
   {
     "LazyVim/LazyVim",
     opts = {
-      colorscheme = "catppuccin-nvim",
+      colorscheme = "catppuccin-mocha",
     },
   },
 }