diff --git a/tests/main.py b/tests/main.py
index 6f9112108bc..d89d17fc582 100644
--- a/tests/main.py
+++ b/tests/main.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
 import time
 from datetime import timedelta
diff --git a/tests/parser.py b/tests/parser.py
index f7255530080..7d62911d9db 100644
--- a/tests/parser.py
+++ b/tests/parser.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
 from fnmatch import fnmatch
 from collections import namedtuple
diff --git a/tests/runtime-tests.sh b/tests/runtime-tests.sh
index d2b39d9222c..4a524d3130b 100755
--- a/tests/runtime-tests.sh
+++ b/tests/runtime-tests.sh
@@ -7,4 +7,4 @@ DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 BPFTRACE_RUNTIME_TEST_EXECUTABLE=${BPFTRACE_RUNTIME_TEST_EXECUTABLE:-$DIR/../src/};
 export BPFTRACE_RUNTIME_TEST_EXECUTABLE;
 
-python main.py $@
+python3 main.py $@
diff --git a/tests/runtime/basic b/tests/runtime/basic
index 9dc48f59668..305c3417f09 100644
--- a/tests/runtime/basic
+++ b/tests/runtime/basic
@@ -15,7 +15,7 @@ TIMEOUT 1
 
 NAME errors on non existent file
 RUN bpftrace non_existent_file.bt
-EXPECT Error: Could not open file 'non_existent_file.bt'
+EXPECT Error opening file 'non_existent_file.bt': No such file or directory
 TIMEOUT 1
 
 NAME it lists kprobes
diff --git a/tests/utils.py b/tests/utils.py
index 533a9520f00..eb1f1632e18 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -1,3 +1,5 @@
+#!/usr/bin/python3
+
 import subprocess
 import signal
 from os import environ, uname, devnull
@@ -101,14 +103,14 @@ def run_test(test):
 
             while p.poll() is None:
                 nextline = p.stdout.readline()
-                output += nextline
+                output += nextline.decode()
                 if nextline == "Running...\n":
                     signal.alarm(test.timeout or DEFAULT_TIMEOUT)
                     if not after and test.after:
                         after = subprocess.Popen(test.after, shell=True)
                     break
 
-            output += p.communicate()[0]
+            output += p.communicate()[0].decode()
 
             signal.alarm(0)
             result = re.search(test.expect, output)
@@ -118,7 +120,7 @@ def run_test(test):
             # bpftrace process might still be alive
             if p.poll() is None:
                 p.kill()
-            output += p.communicate()[0]
+            output += p.communicate()[0].decode()
             result = re.search(test.expect, output)
             if not result:
                 print(fail("[  TIMEOUT ] ") + "%s.%s" % (test.suite, test.name))