diff --git a/acceptance/bin/sort_lines.py b/acceptance/bin/sort_lines.py
new file mode 100755
index 000000000..e7b8256e4
--- /dev/null
+++ b/acceptance/bin/sort_lines.py
@@ -0,0 +1,8 @@
+#!/usr/bin/env python3
+"""
+Helper to sort lines in text file. Similar to 'sort' but no dependence on locale or presence of 'sort' in PATH.
+"""
+import sys
+lines = sys.stdin.readlines()
+lines.sort()
+sys.stdout.write("".join(lines))
diff --git a/acceptance/bundle/debug/script b/acceptance/bundle/debug/script
index b0e5f4503..7cd88e20f 100644
--- a/acceptance/bundle/debug/script
+++ b/acceptance/bundle/debug/script
@@ -1,3 +1,3 @@
 $CLI bundle validate --debug > out.stdout.txt 2> full.stderr.txt
 grep -vw parallel full.stderr.txt > out.stderr.txt
-grep -w parallel full.stderr.txt | sort > out.stderr.parallel.txt
+grep -w parallel full.stderr.txt | sort_lines.py > out.stderr.parallel.txt