diff --git a/lib/core/settings.py b/lib/core/settings.py
index 4501c904b..3a8834415 100644
--- a/lib/core/settings.py
+++ b/lib/core/settings.py
@@ -20,7 +20,7 @@ from thirdparty import six
 from thirdparty.six import unichr as _unichr
 
 # sqlmap version (<major>.<minor>.<month>.<monthly commit>)
-VERSION = "1.5.8.7"
+VERSION = "1.5.8.8"
 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/request/connect.py b/lib/request/connect.py
index d5248cb5b..0cc83b244 100644
--- a/lib/request/connect.py
+++ b/lib/request/connect.py
@@ -978,7 +978,7 @@ class Connect(object):
 
         if conf.httpHeaders:
             headers = OrderedDict(conf.httpHeaders)
-            contentType = max(headers[_] if _.upper() == HTTP_HEADER.CONTENT_TYPE.upper() else "" for _ in headers) or None
+            contentType = max(headers[_] or "" if _.upper() == HTTP_HEADER.CONTENT_TYPE.upper() else "" for _ in headers) or None
 
             if (kb.postHint or conf.skipUrlEncode) and postUrlEncode:
                 postUrlEncode = False