diff --git a/pyipmi/errors.py b/pyipmi/errors.py
index 828a17d..9d10cc1 100644
--- a/pyipmi/errors.py
+++ b/pyipmi/errors.py
@@ -90,3 +90,12 @@ def __init__(self, msg=None):
 
     def __str__(self):
         return "{}".format(self.msg)
+
+
+class IpmiLongPasswordError(Exception):
+    """Password longer than 20 bytes."""
+    def __init__(self, msg=None):
+        self.msg = msg
+
+    def __str__(self):
+        return "{}".format(self.msg)
diff --git a/pyipmi/interfaces/ipmitool.py b/pyipmi/interfaces/ipmitool.py
index f2c1b54..815041a 100644
--- a/pyipmi/interfaces/ipmitool.py
+++ b/pyipmi/interfaces/ipmitool.py
@@ -21,7 +21,7 @@
 from array import array
 
 from ..session import Session
-from ..errors import IpmiTimeoutError, IpmiConnectionError
+from ..errors import IpmiTimeoutError, IpmiConnectionError, IpmiLongPasswordError
 from ..logger import log
 from ..msgs import encode_message, decode_message, create_message
 from ..msgs.constants import CC_OK
@@ -62,7 +62,8 @@ def __init__(self, interface_type='lan', cipher=None):
                 r".*Unable to establish.*")
         self.re_could_not_open = re.compile(
                 r".*Could not open device.*")
-
+        self.re_long_password = re.compile(
+                r".*password is longer than.*")
         self._session = None
 
     def open(self):
@@ -135,6 +136,9 @@ def _parse_output(self, output):
             if self.re_could_not_open.match(line):
                 raise RuntimeError('ipmitool failed: {}'.format(output))
 
+            if self.re_long_password.match(line):
+                raise IpmiLongPasswordError(line)
+
             hexstr += line.replace('\r', '').strip() + ' '
 
         hexstr = hexstr.strip()
diff --git a/tests/interfaces/test_ipmitool.py b/tests/interfaces/test_ipmitool.py
index cbe1c46..0d4f860 100644
--- a/tests/interfaces/test_ipmitool.py
+++ b/tests/interfaces/test_ipmitool.py
@@ -5,7 +5,7 @@
 
 import pytest
 
-from pyipmi.errors import IpmiTimeoutError, IpmiConnectionError
+from pyipmi.errors import IpmiTimeoutError, IpmiConnectionError, IpmiLongPasswordError
 from pyipmi.interfaces import Ipmitool
 from pyipmi import Session, Target
 from pyipmi.utils import py3_array_tobytes
@@ -223,3 +223,9 @@ def test_parse_output_connection_error_rmcp(self):
         with pytest.raises(IpmiConnectionError):
             cc, rsp = self._interface._parse_output(test_str)
             assert rsp is None
+
+    def test_parse_long_password_error(self):
+        test_str = b'lanplus: password is longer than 20 bytes.'
+        with pytest.raises(IpmiLongPasswordError):
+            cc, rsp = self._interface._parse_output(test_str)
+            assert rsp is None