diff --git a/lib/core/common.py b/lib/core/common.py
index 885cdaac5..c1271be4c 100644
--- a/lib/core/common.py
+++ b/lib/core/common.py
@@ -2908,15 +2908,15 @@ def filterStringValue(value, charRegex, replacement=""):
 
     return retVal
 
-def filterControlChars(value):
+def filterControlChars(value, replacement=' '):
     """
-    Returns string value with control chars being supstituted with ' '
+    Returns string value with control chars being supstituted with replacement character
 
     >>> filterControlChars(u'AND 1>(2+3)\\n--')
     u'AND 1>(2+3) --'
     """
 
-    return filterStringValue(value, PRINTABLE_CHAR_REGEX, ' ')
+    return filterStringValue(value, PRINTABLE_CHAR_REGEX, replacement)
 
 def isDBMSVersionAtLeast(version):
     """
diff --git a/lib/core/settings.py b/lib/core/settings.py
index 3e54a786d..592795b7f 100644
--- a/lib/core/settings.py
+++ b/lib/core/settings.py
@@ -19,7 +19,7 @@ from lib.core.enums import DBMS_DIRECTORY_NAME
 from lib.core.enums import OS
 
 # sqlmap version (<major>.<minor>.<month>.<monthly commit>)
-VERSION = "1.2.8.0"
+VERSION = "1.2.8.1"
 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 4dca1afb4..484666e0c 100644
--- a/lib/techniques/blind/inference.py
+++ b/lib/techniques/blind/inference.py
@@ -501,7 +501,7 @@ def bisection(payload, expression, length=None, charsetType=None, firstChar=None
                                 count = threadData.shared.start
 
                                 for i in xrange(startCharIndex, endCharIndex + 1):
-                                    output += '_' if currentValue[i] is None else currentValue[i]
+                                    output += '_' if currentValue[i] is None else filterControlChars(currentValue[i] if len(currentValue[i]) == 1 else ' ', replacement=' ')
 
                                 for i in xrange(length):
                                     count += 1 if currentValue[i] is not None else 0
@@ -518,7 +518,7 @@ def bisection(payload, expression, length=None, charsetType=None, firstChar=None
                                     status = ' %d/%d (%d%%)' % (_, length, int(100.0 * _ / length))
                                     output += status if _ != length else " " * len(status)
 
-                                    dataToStdout("\r[%s] [INFO] retrieved: %s" % (time.strftime("%X"), filterControlChars(output)))
+                                    dataToStdout("\r[%s] [INFO] retrieved: %s" % (time.strftime("%X"), output))
 
                 runThreads(numThreads, blindThread, startThreadMsg=False)
 
diff --git a/txt/checksum.md5 b/txt/checksum.md5
index f349a738e..7330bb9d5 100644
--- a/txt/checksum.md5
+++ b/txt/checksum.md5
@@ -28,7 +28,7 @@ c7443613a0a2505b1faec931cee2a6ef  lib/controller/handler.py
 1e5532ede194ac9c083891c2f02bca93  lib/controller/__init__.py
 0adf547455a76dc71e6a599e52da1ed9  lib/core/agent.py
 fd8f239e259afaf5f24bcf34a0ad187f  lib/core/bigarray.py
-ee1b800e860263b877a2b292a3e4becd  lib/core/common.py
+655326aed648209c5477464825cebea8  lib/core/common.py
 0d082da16c388b3445e656e0760fb582  lib/core/convert.py
 9f87391b6a3395f7f50830b391264f27  lib/core/data.py
 72016ea5c994a711a262fd64572a0fcd  lib/core/datatype.py
@@ -48,7 +48,7 @@ c8c386d644d57c659d74542f5f57f632  lib/core/patch.py
 0c3eef46bdbf87e29a3f95f90240d192  lib/core/replication.py
 a7db43859b61569b601b97f187dd31c5  lib/core/revision.py
 fcb74fcc9577523524659ec49e2e964b  lib/core/session.py
-355a1680a1f53013390849ca50322c0e  lib/core/settings.py
+63ca523cd15143c4c0dc1ee2d307dfa6  lib/core/settings.py
 dd68a9d02fccb4fa1428b20e15b0db5d  lib/core/shell.py
 a7edc9250d13af36ac0108f259859c19  lib/core/subprocessng.py
 12bed9603b6fba3e5ffda11d584bc449  lib/core/target.py
@@ -89,7 +89,7 @@ fb9e34d558293b5d6b9727f440712886  lib/takeover/registry.py
 48575dde7bb867b7937769f569a98309  lib/takeover/udf.py
 f6f835e4190a55e42d13c1e7ca3f728f  lib/takeover/web.py
 debc36a3ff80ba915aeeee69b21a8ddc  lib/takeover/xp_cmdshell.py
-0e9d37cbeabd1bbbfe2c53f01bbb6a6e  lib/techniques/blind/inference.py
+db208ab47de010836c6bf044e2357861  lib/techniques/blind/inference.py
 1e5532ede194ac9c083891c2f02bca93  lib/techniques/blind/__init__.py
 1e5532ede194ac9c083891c2f02bca93  lib/techniques/dns/__init__.py
 799faf9008527d2e9da9d923e50f685a  lib/techniques/dns/test.py