diff --git a/tests/test_write_devstack_local_conf_role.sh b/tests/test_write_devstack_local_conf_role.sh
index b2bc0a2c46..71d8d51614 100755
--- a/tests/test_write_devstack_local_conf_role.sh
+++ b/tests/test_write_devstack_local_conf_role.sh
@@ -6,4 +6,4 @@ TOP=$(cd $(dirname "$0")/.. && pwd)
 source $TOP/functions
 source $TOP/tests/unittest.sh
 
-python ./roles/write-devstack-local-conf/library/test.py
+${PYTHON} $TOP/roles/write-devstack-local-conf/library/test.py
diff --git a/tests/unittest.sh b/tests/unittest.sh
index 3703ece91d..fced2abe65 100644
--- a/tests/unittest.sh
+++ b/tests/unittest.sh
@@ -17,6 +17,8 @@ ERROR=0
 PASS=0
 FAILED_FUNCS=""
 
+export PYTHON=$(which python3 2>/dev/null)
+
 # pass a test, printing out MSG
 #  usage: passed message
 function passed {