diff --git a/lib/core/decorators.py b/lib/core/decorators.py
index d8e3f8829..f99c712c9 100644
--- a/lib/core/decorators.py
+++ b/lib/core/decorators.py
@@ -27,7 +27,8 @@ def cachedmethod(f, cache=LRUDict(capacity=MAX_CACHE_ITEMS)):
         key = int(hashlib.md5("|".join(str(_) for _ in (f, args, kwargs))).hexdigest(), 16) & 0x7fffffffffffffff
 
         try:
-            result = cache[key]
+            with _lock:
+                result = cache[key]
         except KeyError:
             result = f(*args, **kwargs)
 
diff --git a/lib/core/settings.py b/lib/core/settings.py
index 6e613fe34..c16282034 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 = "1.3.2.19"
+VERSION = "1.3.2.20"
 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)
diff --git a/txt/checksum.md5 b/txt/checksum.md5
index 7d30114ad..99ab41c60 100644
--- a/txt/checksum.md5
+++ b/txt/checksum.md5
@@ -34,7 +34,7 @@ a932126e7d80e545c5d44af178d0bc0c  lib/core/bigarray.py
 de8d27ae6241163ff9e97aa9e7c51a18  lib/core/convert.py
 abcb1121eb56d3401839d14e8ed06b6e  lib/core/data.py
 00828c4455321b6987e3f882f4ef4f92  lib/core/datatype.py
-3ec93893ad8b1e060540753b7f8a8caf  lib/core/decorators.py
+3d547dedebef3be749cf38e4e798e120  lib/core/decorators.py
 5f4680b769ae07f22157bd832c97cf8f  lib/core/defaults.py
 9dfc69ba47209a4ceca494dde9ee8183  lib/core/dicts.py
 4ba141124699fd7a763dea82f17fe523  lib/core/dump.py
@@ -50,7 +50,7 @@ d5ef43fe3cdd6c2602d7db45651f9ceb  lib/core/readlineng.py
 7d8a22c582ad201f65b73225e4456170  lib/core/replication.py
 3179d34f371e0295dd4604568fb30bcd  lib/core/revision.py
 d6269c55789f78cf707e09a0f5b45443  lib/core/session.py
-587adf8926007e3e73492e136bc74da4  lib/core/settings.py
+be40d085a10a86d6f324039d76d48afa  lib/core/settings.py
 4483b4a5b601d8f1c4281071dff21ecc  lib/core/shell.py
 10fd19b0716ed261e6d04f311f6f527c  lib/core/subprocessng.py
 43772ea73e9e3d446f782af591cb4eda  lib/core/target.py