diff --git a/lib/core/decorators.py b/lib/core/decorators.py
index 8ddf00c63..85417b757 100644
--- a/lib/core/decorators.py
+++ b/lib/core/decorators.py
@@ -39,16 +39,19 @@ def cachedmethod(f):
 
     @functools.wraps(f)
     def _f(*args, **kwargs):
-        key = int(hashlib.md5("|".join(str(_) for _ in (f, args, kwargs)).encode(UNICODE_ENCODING)).hexdigest(), 16) & 0x7fffffffffffffff
-
         try:
-            with _cache_lock:
-                result = _cache[f][key]
-        except KeyError:
+            key = int(hashlib.md5("|".join(str(_) for _ in (f, args, kwargs)).encode(UNICODE_ENCODING)).hexdigest(), 16) & 0x7fffffffffffffff
+        except ValueError:  # https://github.com/sqlmapproject/sqlmap/issues/4281 (NOTE: non-standard Python behavior where hexdigest returns binary value)
             result = f(*args, **kwargs)
+        else:
+            try:
+                with _cache_lock:
+                    result = _cache[f][key]
+            except KeyError:
+                result = f(*args, **kwargs)
 
-            with _cache_lock:
-                _cache[f][key] = result
+                with _cache_lock:
+                    _cache[f][key] = result
 
         return result
 
diff --git a/lib/core/settings.py b/lib/core/settings.py
index 3f2e1d58b..4b10492e6 100644
--- a/lib/core/settings.py
+++ b/lib/core/settings.py
@@ -18,7 +18,7 @@ from lib.core.enums import OS
 from thirdparty.six import unichr as _unichr
 
 # sqlmap version (<major>.<minor>.<month>.<monthly commit>)
-VERSION = "1.4.7.17"
+VERSION = "1.4.7.18"
 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)