diff --git a/lib/core/settings.py b/lib/core/settings.py
index 0eee8191e..256035d3b 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 = "1.5.3.2"
+VERSION = "1.5.3.3"
 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/techniques/blind/inference.py b/lib/techniques/blind/inference.py
index 0ec4c3c60..739d26533 100644
--- a/lib/techniques/blind/inference.py
+++ b/lib/techniques/blind/inference.py
@@ -217,7 +217,7 @@ def bisection(payload, expression, length=None, charsetType=None, firstChar=None
 
                 markingValue = "'%s'" % CHAR_INFERENCE_MARK
                 unescapedCharValue = unescaper.escape("'%s'" % decodeIntToUnicode(posValue))
-                forgedPayload = agent.extractPayload(payload)
+                forgedPayload = agent.extractPayload(payload) or ""
                 forgedPayload = safeStringFormat(forgedPayload.replace(INFERENCE_GREATER_CHAR, INFERENCE_EQUALS_CHAR), (expressionUnescaped, idx, posValue)).replace(markingValue, unescapedCharValue)
                 result = Request.queryPage(agent.replacePayload(payload, forgedPayload), timeBasedCompare=timeBasedCompare, raise404=False)
                 incrementCounter(getTechnique())