diff --git a/lib/core/common.py b/lib/core/common.py
index bb1c635c9..bb749e7af 100644
--- a/lib/core/common.py
+++ b/lib/core/common.py
@@ -2151,14 +2151,20 @@ def shellExec(cmd):
     """
     Executes arbitrary shell command
 
-    >>> shellExec('echo 1').strip() == b'1'
+    >>> shellExec('echo 1').strip() == '1'
     True
     """
 
+    retVal = ""
+
     try:
-        return subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT).communicate()[0] or ""
+        retVal = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT).communicate()[0] or ""
     except Exception as ex:
-        return six.text_type(ex)
+        retVal = getSafeExString(ex)
+    finally:
+        retVal = getText(retVal)
+
+    return retVal
 
 def clearConsoleLine(forceOutput=False):
     """
diff --git a/lib/core/revision.py b/lib/core/revision.py
index 277d1f5f6..063761875 100644
--- a/lib/core/revision.py
+++ b/lib/core/revision.py
@@ -9,6 +9,8 @@ import os
 import re
 import subprocess
 
+from lib.core.common import getText
+
 def getRevisionNumber():
     """
     Returns abbreviated commit hash number as retrieved with "git rev-parse --short HEAD"
@@ -50,7 +52,7 @@ def getRevisionNumber():
         try:
             process = subprocess.Popen("git rev-parse --verify HEAD", shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
             stdout, _ = process.communicate()
-            match = re.search(r"(?i)[0-9a-f]{32}", stdout or "")
+            match = re.search(r"(?i)[0-9a-f]{32}", getText(stdout or ""))
             retVal = match.group(0) if match else None
         except:
             pass
diff --git a/lib/core/settings.py b/lib/core/settings.py
index 24755dd33..77af8c08d 100644
--- a/lib/core/settings.py
+++ b/lib/core/settings.py
@@ -18,7 +18,7 @@ from lib.core.enums import OS
 from thirdparty import six
 
 # sqlmap version (<major>.<minor>.<month>.<monthly commit>)
-VERSION = "1.3.5.80"
+VERSION = "1.3.5.81"
 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/core/testing.py b/lib/core/testing.py
index 24d34ab1a..fd7e9ba06 100644
--- a/lib/core/testing.py
+++ b/lib/core/testing.py
@@ -80,7 +80,6 @@ def vulnTest():
     ):
         cmd = "%s %s -u http://%s:%d/?id=1 --batch %s" % (sys.executable, os.path.join(os.path.dirname(__file__), "..", "..", "sqlmap.py"), address, port, options)
         output = shellExec(cmd)
-        output = getUnicode(output)
 
         if not all(check in output for check in checks):
             dataToStdout("---\n\n$ %s\n" % cmd)
diff --git a/lib/core/update.py b/lib/core/update.py
index 39b221e14..8cbaf37d6 100644
--- a/lib/core/update.py
+++ b/lib/core/update.py
@@ -17,6 +17,7 @@ import zipfile
 from lib.core.common import dataToStdout
 from lib.core.common import getSafeExString
 from lib.core.common import getLatestRevision
+from lib.core.common import getText
 from lib.core.common import pollProcess
 from lib.core.common import readInput
 from lib.core.data import conf
@@ -106,23 +107,25 @@ def update():
         dataToStdout("\r[%s] [INFO] update in progress" % time.strftime("%X"))
 
         try:
-            process = subprocess.Popen("git checkout . && git pull %s HEAD" % GIT_REPOSITORY, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=paths.SQLMAP_ROOT_PATH.encode(sys.getfilesystemencoding() or UNICODE_ENCODING))
+            process = subprocess.Popen("git checkout . && git pull %s HEAD" % GIT_REPOSITORY, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, cwd=paths.SQLMAP_ROOT_PATH.encode(sys.getfilesystemencoding() or UNICODE_ENCODING))
             pollProcess(process, True)
-            stdout, stderr = process.communicate()
+            output, _ = process.communicate()
             success = not process.returncode
         except (IOError, OSError) as ex:
             success = False
-            stderr = getSafeExString(ex)
+            output = getSafeExString(ex)
+        finally:
+            output = getText(output)
 
         if success:
-            logger.info("%s the latest revision '%s'" % ("already at" if "Already" in stdout else "updated to", getRevisionNumber()))
+            logger.info("%s the latest revision '%s'" % ("already at" if "Already" in output else "updated to", getRevisionNumber()))
         else:
-            if "Not a git repository" in stderr:
+            if "Not a git repository" in output:
                 errMsg = "not a valid git repository. Please checkout the 'sqlmapproject/sqlmap' repository "
                 errMsg += "from GitHub (e.g. 'git clone --depth 1 %s sqlmap')" % GIT_REPOSITORY
                 logger.error(errMsg)
             else:
-                logger.error("update could not be completed ('%s')" % re.sub(r"\W+", " ", stderr).strip())
+                logger.error("update could not be completed ('%s')" % re.sub(r"\W+", " ", output).strip())
 
     if not success:
         if IS_WIN: