diff --git a/tools/perf/scripts/python/parallel-perf.py b/tools/perf/scripts/python/parallel-perf.py
index 21f32ec5ed46..be85fd7f6632 100755
--- a/tools/perf/scripts/python/parallel-perf.py
+++ b/tools/perf/scripts/python/parallel-perf.py
@@ -439,7 +439,8 @@ def ProcessCommandOutputLines(cmd, per_cpu, fn, *x):
 	pat = re.compile(r"\s*\[[0-9]+\]")
 	p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
 	while True:
-		if line := p.stdout.readline():
+		line = p.stdout.readline()
+		if line:
 			line = line.decode("utf-8")
 			if pat.match(line):
 				line = line.split()