diff --git a/lib/cli.js b/lib/cli.js
index a3af414..0c918c4 100644
--- a/lib/cli.js
+++ b/lib/cli.js
@@ -6,7 +6,7 @@
 
 const co = require('co')
 const argx = require('argx')
-const ponfile = require('ponfile')
+const runnable = require('./runnable')
 
 /** @lends cli */
 function cli (name, options) {
@@ -18,7 +18,7 @@ function cli (name, options) {
     list = false
   } = options
   return co(function * () {
-    let runner = ponfile(cwd)
+    let runner = runnable(cwd)
     if (list) {
       let pattern = typeof list === 'string' ? list : null
       return cli.list(runner.tasks, { pattern })
@@ -26,13 +26,7 @@ function cli (name, options) {
     if (names && names.length > 0) {
       let results = []
       for (let name of names) {
-        let result = yield Promise.resolve(runner.run(name)).then((result) => {
-          let isEmpty = Object.keys(result).length === 0
-          if (isEmpty) {
-            console.warn(`No task found for name: "${name}"`)
-          }
-          return result
-        })
+        let result = yield Promise.resolve(runner.run(name))
         results.push(result)
       }
       return results
diff --git a/lib/runnable.js b/lib/runnable.js
new file mode 100644
index 0000000..56c252d
--- /dev/null
+++ b/lib/runnable.js
@@ -0,0 +1,28 @@
+/**
+ * Define CLI Runner
+ * @function runnable
+ * @param {string} cwd - Working directory
+ * @returns {CLIRunner} Runner instance
+ */
+'use strict'
+const { Ponfile } = require('ponfile')
+
+/**
+ * Runner implementation for CLI
+ */
+class CLIRunner extends Ponfile {
+  run (...patterns) {
+    return Promise.resolve(
+      super.run(...arguments)
+    ).then((result) => {
+      let isEmpty = Object.keys(result).length === 0
+      if (isEmpty) {
+        let specified = patterns.length > 1 ? patterns : patterns[ 0 ]
+        console.warn(`No task found for: ${JSON.stringify(specified)}`)
+      }
+      return result
+    })
+  }
+}
+
+module.exports = (cwd) => new CLIRunner(cwd)
diff --git a/misc/mock/mock-project-01/Ponfile.js b/misc/mock/mock-project-01/Ponfile.js
index 59db44b..526d559 100644
--- a/misc/mock/mock-project-01/Ponfile.js
+++ b/misc/mock/mock-project-01/Ponfile.js
@@ -12,6 +12,9 @@ module.exports = ponRunner({
   },
   b () {
     console.log('This is B')
-  }
+  },
+
+  invalid01: [ '__invalid_pointer_01__', () => {} ],
+  invalid02: [ '__invalid_pointer_02__' ]
 }).bind()
 
diff --git a/test/cli_test.js b/test/cli_test.js
index 3cd1811..73dfc1a 100644
--- a/test/cli_test.js
+++ b/test/cli_test.js
@@ -49,6 +49,16 @@ describe('cli', function () {
       list: true
     })
   }))
+
+  // https://github.com/realglobe-Inc/pon/issues/13
+  it('Warning with not existing task', () => co(function * () {
+    yield cli('invalid01', {
+      cwd: `${__dirname}/../misc/mock/mock-project-01`
+    })
+    yield cli('invalid02', {
+      cwd: `${__dirname}/../misc/mock/mock-project-01`
+    })
+  }))
 })
 
 /* global describe, before, after, it */