diff --git a/lib/core/settings.py b/lib/core/settings.py
index 9487749ce..9ede1a7ec 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 = "1.4.1.65"
+VERSION = "1.4.1.66"
 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/lib/parse/html.py b/lib/parse/html.py
index 68fe55621..a1e412ebf 100644
--- a/lib/parse/html.py
+++ b/lib/parse/html.py
@@ -26,7 +26,10 @@ class HTMLHandler(ContentHandler):
 
         self._dbms = None
         self._page = (page or "")
-        self._lower_page = self._page.lower()
+        try:
+            self._lower_page = self._page.lower()
+        except SystemError:  # https://bugs.python.org/issue18183
+            self._lower_page = None
         self._urldecoded_page = urldecode(self._page)
 
         self.dbms = None
@@ -49,7 +52,7 @@ class HTMLHandler(ContentHandler):
                 keywords = sorted(keywords, key=len)
                 kb.cache.regex[regexp] = keywords[-1].lower()
 
-            if kb.cache.regex[regexp] in self._lower_page and re.search(regexp, self._urldecoded_page, re.I):
+            if kb.cache.regex[regexp] in (self._lower_page or kb.cache.regex[regexp]) and re.search(regexp, self._urldecoded_page, re.I):
                 self.dbms = self._dbms
                 self._markAsErrorPage()
                 kb.forkNote = kb.forkNote or attrs.get("fork")