diff --git a/certbot/hooks.py b/certbot/hooks.py
index 6757c5a72..ae190a930 100644
--- a/certbot/hooks.py
+++ b/certbot/hooks.py
@@ -20,13 +20,19 @@ def validate_hooks(config):
     validate_hook(config.renew_hook, "renew")
 
 def _prog(shell_cmd):
-    """Extract the program run by a shell command"""
-    cmd = util.which(shell_cmd)
-    if not cmd:
-        plug_util.path_surgery(shell_cmd)
-        cmd = util.which(shell_cmd)
+    """Extract the program run by a shell command.
 
-    return os.path.basename(cmd) if cmd else None
+    :param str shell_cmd: command to be executed
+
+    :returns: basename of command or None if the command isn't found
+    :rtype: str or None
+
+    """
+    if not util.exe_exists(shell_cmd):
+        plug_util.path_surgery(shell_cmd)
+        if not util.exe_exists(shell_cmd):
+            return None
+    return os.path.basename(shell_cmd)
 
 
 def validate_hook(shell_cmd, hook_name):
@@ -117,6 +123,7 @@ def execute(shell_cmd):
         logger.error('Hook command "%s" returned error code %d',
                      shell_cmd, cmd.returncode)
     if err:
-        logger.error('Error output from %s:\n%s', _prog(shell_cmd), err)
+        base_cmd = os.path.basename(shell_cmd.split(None, 1)[0])
+        logger.error('Error output from %s:\n%s', base_cmd, err)
     return (err, out)
 
diff --git a/certbot/tests/hook_test.py b/certbot/tests/hook_test.py
index f799ed74f..a8f49745b 100644
--- a/certbot/tests/hook_test.py
+++ b/certbot/tests/hook_test.py
@@ -27,13 +27,13 @@ class HookTest(unittest.TestCase):
         config = mock.MagicMock(pre_hook="explodinator", post_hook="", renew_hook="")
         self.assertRaises(errors.HookCommandNotFound, hooks.validate_hooks, config)
 
-    @mock.patch('certbot.hooks.util.which')
+    @mock.patch('certbot.hooks.util.exe_exists')
     @mock.patch('certbot.hooks.plug_util.path_surgery')
-    def test_prog(self, mock_ps, mockwhich):
-        mockwhich.return_value = "/very/very/funky"
+    def test_prog(self, mock_ps, mock_exe_exists):
+        mock_exe_exists.return_value = True
         self.assertEqual(hooks._prog("funky"), "funky")
         self.assertEqual(mock_ps.call_count, 0)
-        mockwhich.return_value = None
+        mock_exe_exists.return_value = False
         self.assertEqual(hooks._prog("funky"), None)
         self.assertEqual(mock_ps.call_count, 1)