diff --git a/lua/glaze/runner.lua b/lua/glaze/runner.lua
index 1d2ae10..11f672d 100644
--- a/lua/glaze/runner.lua
+++ b/lua/glaze/runner.lua
@@ -111,6 +111,25 @@ local function run_task(task)
       M._process_queue()
     end,
   })
+
+  if task.job_id <= 0 then
+    task.end_time = vim.uv.hrtime()
+    task.status = "error"
+    table.insert(task.output, "Failed to start command: " .. table.concat(cmd, " "))
+    task.job_id = nil
+
+    -- Call all registered callbacks with failure
+    if task.binary.callbacks then
+      vim.schedule(function()
+        for _, cb in pairs(task.binary.callbacks) do
+          cb(false)
+        end
+      end)
+    end
+
+    M._notify()
+    vim.schedule(M._process_queue)
+  end
 end
 
 ---@private
@@ -166,18 +185,12 @@ local function run(names, mode, opts)
 
   for _, name in ipairs(names) do
     local binary = glaze._binaries[name]
-    if binary then
-      if existing_names[name] then
-        -- Already queued or running, skip
-      elseif mode == "install" and glaze.is_installed(name) then
-        -- Skip already installed
-      else
-        table.insert(binaries, binary)
-      end
-    else
+    if not binary then
       if not opts.silent then
         vim.notify("Unknown binary: " .. name, vim.log.levels.WARN)
       end
+    elseif not existing_names[name] and not (mode == "install" and glaze.is_installed(name)) then
+      table.insert(binaries, binary)
     end
   end
 
diff --git a/tests/run.lua b/tests/run.lua
index 36ad265..ed1db52 100644
--- a/tests/run.lua
+++ b/tests/run.lua
@@ -107,6 +107,38 @@ test("register merges duplicate plugin registrations without duplicates", functi
   assert_eq(binary.plugins[2], "freeze.nvim")
 end)
 
+test("runner marks failed job starts as errors", function()
+  local glaze = reset_glaze()
+  local runner = require("glaze.runner")
+  local original_jobstart = vim.fn.jobstart
+
+  local callback_result = "unset"
+  glaze.setup({ auto_check = { enabled = false }, auto_install = { enabled = false } })
+  glaze.register("fake-glaze-binary", "example.com/fake/glaze", {
+    plugin = "fake.nvim",
+    callback = function(success)
+      callback_result = success
+    end,
+  })
+  glaze.is_installed = function()
+    return false
+  end
+  vim.fn.jobstart = function()
+    return -1
+  end
+
+  runner.install({ "fake-glaze-binary" }, { silent = true })
+  vim.wait(100)
+  vim.fn.jobstart = original_jobstart
+
+  local tasks = runner.tasks()
+  assert_eq(#tasks, 1, "failed job start should create one task")
+  assert_eq(tasks[1].status, "error", "failed job start should mark task as error")
+  assert_truthy(tasks[1].output[1]:match("Failed to start command"), "failed job start should keep output")
+  assert_eq(runner.is_running(), false, "failed job start should drain the runner")
+  assert_eq(callback_result, false, "failed job start should notify callbacks with false")
+end)
+
 for _, case in ipairs(results) do
   local ok, err = pcall(case.fn)
   if not ok then