diff --git a/lib/core/datatype.py b/lib/core/datatype.py
index 079222d1a..d32386f06 100644
--- a/lib/core/datatype.py
+++ b/lib/core/datatype.py
@@ -8,6 +8,8 @@ See the file 'LICENSE' for copying permission
 import copy
 import types
 
+from thirdparty.odict.odict import OrderedDict
+
 class AttribDict(dict):
     """
     This class defines the sqlmap object, inheriting from Python data
@@ -104,3 +106,40 @@ class InjectionDict(AttribDict):
         self.dbms = None
         self.dbms_version = None
         self.os = None
+
+# Reference: https://www.kunxi.org/2014/05/lru-cache-in-python
+class LRUDict(object):
+    def __init__(self, capacity):
+        self.capacity = capacity
+        self.cache = OrderedDict()
+
+    def __len__(self):
+        return len(self.cache)
+
+    def __contains__(self, key):
+        return key in self.cache
+
+    def __getitem__(self, key):
+        try:
+            value = self.cache.pop(key)
+            self.cache[key] = value
+            return value
+        except KeyError:
+            return -1
+
+    def get(self, key):
+        return self.__getitem__(self, key)
+
+    def __setitem__(self, key, value):
+        try:
+            self.cache.pop(key)
+        except KeyError:
+            if len(self.cache) >= self.capacity:
+                self.cache.popitem(last=False)
+        self.cache[key] = value
+
+    def set(self, key, value):
+        self.__setitem__(key, value)
+
+    def keys(self):
+        return self.cache.keys()
diff --git a/lib/core/decorators.py b/lib/core/decorators.py
index 3ceaa55c9..ecc29d58e 100644
--- a/lib/core/decorators.py
+++ b/lib/core/decorators.py
@@ -7,10 +7,15 @@ See the file 'LICENSE' for copying permission
 
 import functools
 import hashlib
+import threading
 
+from lib.core.settings import MAX_CACHE_ITEMS
+from lib.core.datatype import LRUDict
 from lib.core.threads import getCurrentThreadData
 
-def cachedmethod(f, cache={}):
+_lock = threading.Lock()
+
+def cachedmethod(f, cache=LRUDict(capacity=MAX_CACHE_ITEMS)):
     """
     Method with a cached content
 
@@ -19,11 +24,12 @@ def cachedmethod(f, cache={}):
 
     @functools.wraps(f)
     def _(*args, **kwargs):
-        key = int(hashlib.md5("|".join(str(_) for _ in (f, args, kwargs))).hexdigest(), 16) & 0x7fffffffffffffff
-        if key not in cache:
-            cache[key] = f(*args, **kwargs)
+        with _lock:
+            key = int(hashlib.md5("|".join(str(_) for _ in (f, args, kwargs))).hexdigest(), 16) & 0x7fffffffffffffff
+            if key not in cache:
+                cache[key] = f(*args, **kwargs)
 
-        return cache[key]
+            return cache[key]
 
     return _
 
diff --git a/lib/core/settings.py b/lib/core/settings.py
index aa233dfc8..23c824d8e 100644
--- a/lib/core/settings.py
+++ b/lib/core/settings.py
@@ -19,7 +19,7 @@ from lib.core.enums import DBMS_DIRECTORY_NAME
 from lib.core.enums import OS
 
 # sqlmap version (<major>.<minor>.<month>.<monthly commit>)
-VERSION = "1.3.1.80"
+VERSION = "1.3.1.81"
 TYPE = "dev" if VERSION.count('.') > 2 and VERSION.split('.')[-1] != '0' else "stable"
 TYPE_COLORS = {"dev": 33, "stable": 90, "pip": 34}
 VERSION_STRING = "sqlmap/%s#%s" % ('.'.join(VERSION.split('.')[:-1]) if VERSION.count('.') > 2 and VERSION.split('.')[-1] == '0' else VERSION, TYPE)
@@ -166,6 +166,9 @@ MAX_TECHNIQUES_PER_VALUE = 2
 # In case of missing piece of partial union dump, buffered array must be flushed after certain size
 MAX_BUFFERED_PARTIAL_UNION_LENGTH = 1024
 
+# Maximum size of cache used in @cachedmethod decorator
+MAX_CACHE_ITEMS = 256
+
 # Suffix used for naming meta databases in DBMS(es) without explicit database name
 METADB_SUFFIX = "_masterdb"
 
diff --git a/thirdparty/odict/odict.py b/thirdparty/odict/odict.py
index 9b7e9d7be..ee7f2aa24 100644
--- a/thirdparty/odict/odict.py
+++ b/thirdparty/odict/odict.py
@@ -621,7 +621,7 @@ class _OrderedDict(dict):
                 raise KeyError(key)
         return val
 
-    def popitem(self, i=-1):
+    def popitem(self, last=True):
         """
         Delete and return an item specified by index, not a random one as in
         dict. The index is -1 by default (the last item).
@@ -643,6 +643,7 @@ class _OrderedDict(dict):
         if not self._sequence:
             raise KeyError('popitem(): dictionary is empty')
         try:
+            i = -1 if last else 0
             key = self._sequence[i]
         except IndexError:
             raise IndexError('popitem(): index %s not valid' % i)
diff --git a/txt/checksum.md5 b/txt/checksum.md5
index c71c5071b..3e7be18cc 100644
--- a/txt/checksum.md5
+++ b/txt/checksum.md5
@@ -33,8 +33,8 @@ a932126e7d80e545c5d44af178d0bc0c  lib/core/bigarray.py
 f97e6dc62b453cc787ef7f801ee1af5b  lib/core/common.py
 de8d27ae6241163ff9e97aa9e7c51a18  lib/core/convert.py
 abcb1121eb56d3401839d14e8ed06b6e  lib/core/data.py
-db60c6ebb63b72ed119e304b359fc1a6  lib/core/datatype.py
-b7c912e2af7a3354f6d7c04f556a80b2  lib/core/decorators.py
+e1f7758f433202c50426efde5eb96768  lib/core/datatype.py
+1646402a733e564f05025e848b323cf9  lib/core/decorators.py
 5f4680b769ae07f22157bd832c97cf8f  lib/core/defaults.py
 9dfc69ba47209a4ceca494dde9ee8183  lib/core/dicts.py
 4782353a3072e4d17c4e314daf918d8a  lib/core/dump.py
@@ -50,7 +50,7 @@ fe370021c6bc99daf44b2bfc0d1effb3  lib/core/patch.py
 7d8a22c582ad201f65b73225e4456170  lib/core/replication.py
 3179d34f371e0295dd4604568fb30bcd  lib/core/revision.py
 d6269c55789f78cf707e09a0f5b45443  lib/core/session.py
-18eeffa589e845f62a7c0452ba3c373a  lib/core/settings.py
+e9e5e6207591b134c0cf4ecf8e712ea9  lib/core/settings.py
 4483b4a5b601d8f1c4281071dff21ecc  lib/core/shell.py
 10fd19b0716ed261e6d04f311f6f527c  lib/core/subprocessng.py
 9c7b5c6397fb3da33e7a4d7876d159c6  lib/core/target.py
@@ -358,7 +358,7 @@ bf318e0abbe6b2e1a167a233db7f744f  thirdparty/magic/magic.py
 d41d8cd98f00b204e9800998ecf8427e  thirdparty/multipart/__init__.py
 82432cb4ef575aa16900ba221cc1dc98  thirdparty/multipart/multipartpost.py
 3e502b04f3849afbb7f0e13b5fd2b5c1  thirdparty/odict/__init__.py
-4174fad6be204761db349032341b7582  thirdparty/odict/odict.py
+74048dca0470bc78af73f0aafccfd069  thirdparty/odict/odict.py
 0105f1734f326704d2d68839084ca661  thirdparty/oset/_abc.py
 54a861de0f08bb80c2e8846579ec83bd  thirdparty/oset/__init__.py
 6c79e6d14e031beebe6de127b53c7c93  thirdparty/oset/pyoset.py