diff --git a/letsencrypt-auto-source/tests/centos6_tests.sh b/letsencrypt-auto-source/tests/centos6_tests.sh
index 69dbf0fbd..318325a36 100644
--- a/letsencrypt-auto-source/tests/centos6_tests.sh
+++ b/letsencrypt-auto-source/tests/centos6_tests.sh
@@ -47,8 +47,8 @@ if [ $RESULT -eq 0 ]; then
   exit 1
 fi
 
-# Skip self upgrade due to LE_PYTHON value
-if ! LE_PYTHON=nonexistant certbot/letsencrypt-auto-source/letsencrypt-auto 2>&1 | grep -q "WARNING: couldn't find Python"; then
+# Skip self upgrade due to Python 3 not being available.
+if ! certbot/letsencrypt-auto-source/letsencrypt-auto 2>&1 | grep -q "WARNING: couldn't find Python"; then
   echo "Python upgrade failure warning not printed!"
   exit 1
 fi