diff --git a/lib/core/settings.py b/lib/core/settings.py
index 75b13d7ff..6c09af2df 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 = "1.5.1.12"
+VERSION = "1.5.1.13"
 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)
@@ -757,6 +757,8 @@ MAX_CONNECTION_TOTAL_SIZE = 100 * 1024 * 1024
 # For preventing MemoryError exceptions (caused when using large sequences in difflib.SequenceMatcher)
 MAX_DIFFLIB_SEQUENCE_LENGTH = 10 * 1024 * 1024
 
+MAX_CHAR_HEURISTICS_SIZE = 10000
+
 # Maximum (multi-threaded) length of entry in bisection algorithm
 MAX_BISECTION_LENGTH = 50 * 1024 * 1024
 
diff --git a/lib/request/basic.py b/lib/request/basic.py
index db10990c3..ead947cad 100644
--- a/lib/request/basic.py
+++ b/lib/request/basic.py
@@ -44,6 +44,7 @@ from lib.core.settings import BLOCKED_IP_REGEX
 from lib.core.settings import DEFAULT_COOKIE_DELIMITER
 from lib.core.settings import EVENTVALIDATION_REGEX
 from lib.core.settings import IDENTYWAF_PARSE_LIMIT
+from lib.core.settings import MAX_CHAR_HEURISTICS_SIZE
 from lib.core.settings import MAX_CONNECTION_TOTAL_SIZE
 from lib.core.settings import META_CHARSET_REGEX
 from lib.core.settings import PARSE_HEADERS_LIMIT
@@ -258,7 +259,7 @@ def getHeuristicCharEncoding(page):
     """
 
     key = hash(page)
-    retVal = kb.cache.encoding.get(key) or detect(page)["encoding"]
+    retVal = kb.cache.encoding.get(key) or detect(page[:MAX_CHAR_HEURISTICS_SIZE])["encoding"]
     kb.cache.encoding[key] = retVal
 
     if retVal and retVal.lower().replace('-', "") == UNICODE_ENCODING.lower().replace('-', ""):