diff --git a/Tools/autotest/autotest.py b/Tools/autotest/autotest.py
index a19bdf3353..977154d99d 100755
--- a/Tools/autotest/autotest.py
+++ b/Tools/autotest/autotest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """
 ArduPilot automatic test suite.
 
diff --git a/Tools/scripts/build_autotest.sh b/Tools/scripts/build_autotest.sh
index 789c89b6d0..53bd889e5a 100755
--- a/Tools/scripts/build_autotest.sh
+++ b/Tools/scripts/build_autotest.sh
@@ -100,7 +100,7 @@ export BUILD_BINARIES_PATH=$HOME/build/tmp
 # exit on panic so we don't waste time waiting around
 export SITL_PANIC_EXIT=1
 
-timelimit 72000 APM/Tools/autotest/autotest.py --autotest-server --timeout=70000 > buildlogs/autotest-output.txt 2>&1
+timelimit 72000 python3 APM/Tools/autotest/autotest.py --autotest-server --timeout=70000 > buildlogs/autotest-output.txt 2>&1
 
 mkdir -p "buildlogs/history/$hdate"