diff --git a/fuzz/fsfuzzer.py b/fuzz/fsfuzzer.py
index c9aaec9d3..b6a5cae67 100644
--- a/fuzz/fsfuzzer.py
+++ b/fuzz/fsfuzzer.py
@@ -81,7 +81,7 @@ def setUp(self):
         self._args = self.params.get('fstype', default='')
         self._fsfuzz = os.path.abspath(os.path.join('.', "fsfuzz"))
         fs_sup = process.system_output('%s %s' % (self._fsfuzz, ' --help'))
-        match = re.search(r'%s' % self._args, fs_sup, re.M | re.I)
+        match = re.search(br'%s' % self._args, fs_sup, re.M | re.I)
         if not match:
             self.cancel('File system ' + self._args +
                         ' is unsupported in ' + detected_distro.name)
diff --git a/generic/criu.py b/generic/criu.py
index dca4a8f71..7e3a0d100 100755
--- a/generic/criu.py
+++ b/generic/criu.py
@@ -57,7 +57,7 @@ def test(self):
                     ignore_status=True, sudo=True)
         logfile = os.path.join(self.logdir, "stdout")
         failed_tests = process.system_output(
-            "grep -w FAIL %s" % logfile, shell=True, ignore_status=True)
+            "grep -w FAIL %s" % logfile, shell=True, ignore_status=True).decode("utf-8")
         if failed_tests:
             self.fail("test failed, Please check debug log for failed test cases")
 
diff --git a/generic/rcutorture.py b/generic/rcutorture.py
index fcfe6531c..ef303082a 100644
--- a/generic/rcutorture.py
+++ b/generic/rcutorture.py
@@ -101,7 +101,7 @@ def test(self):
             self.cpus_toggle()
         linux_modules.unload_module('rcutorture')
 
-        dmesg = process.system_output('dmesg')
+        dmesg = process.system_output('dmesg').decode("utf-8")
 
         res = re.search(r'rcu-torture: Reader', dmesg, re.M | re.I)
 
diff --git a/generic/sysbench.py b/generic/sysbench.py
index 8dac3a16b..65ff5b2a4 100644
--- a/generic/sysbench.py
+++ b/generic/sysbench.py
@@ -34,7 +34,7 @@ def clear_dmesg(self):
         process.run("dmesg -C ", sudo=True)
 
     def verify_dmesg(self):
-        self.whiteboard = process.system_output("dmesg")
+        self.whiteboard = process.system_output("dmesg").decode("utf-8")
         pattern = ['WARNING: CPU:', 'Oops',
                    'Segfault', 'soft lockup', 'Unable to handle']
         for fail_pattern in pattern: