diff --git a/examples/neovim_luma_preview.lua b/examples/neovim_luma_preview.lua
index 5ed29d9..d26a796 100644
--- a/examples/neovim_luma_preview.lua
+++ b/examples/neovim_luma_preview.lua
@@ -40,7 +40,15 @@ local function update_luma_preview()
   local src_buf = vim.api.nvim_get_current_buf()
   local lines = vim.api.nvim_buf_get_lines(src_buf, 0, -1, false)
   local changedtick = vim.api.nvim_buf_get_changedtick(src_buf)
-  local cmd = vim.env.LUMA_MARKDOWN_BIN or "luma_markdown"
+  local configured_cmd = vim.env.LUMA_MARKDOWN_BIN or "luma_markdown"
+  -- jobstart does not invoke a shell, so expand "~" explicitly. This also
+  -- keeps executable lookup working for a command supplied through PATH.
+  local cmd = vim.fn.expand(configured_cmd)
+
+  if vim.fn.executable(cmd) == 0 then
+    vim.notify("Luma preview executable not found: " .. configured_cmd, vim.log.levels.ERROR)
+    return
+  end
 
   update_id = update_id + 1
   local this_update = update_id
@@ -53,7 +61,7 @@ local function update_luma_preview()
   local output = {}
   local errors = {}
   local job
-  job = vim.fn.jobstart({ cmd }, {
+  local started, result = pcall(vim.fn.jobstart, { cmd }, {
     stdin = "pipe",
     stdout_buffered = true,
     stderr_buffered = true,
@@ -83,11 +91,12 @@ local function update_luma_preview()
     end,
   })
 
-  if job <= 0 then
+  if not started or result <= 0 then
     vim.notify("Could not start Luma preview: " .. cmd, vim.log.levels.ERROR)
     return
   end
 
+  job = result
   active_job = job
   vim.fn.chansend(job, table.concat(lines, "\n"))
   vim.fn.chanclose(job, "stdin")