diff --git a/synapse/metrics/__init__.py b/synapse/metrics/__init__.py
index 64ad762ff1..e33ed6c9be 100644
--- a/synapse/metrics/__init__.py
+++ b/synapse/metrics/__init__.py
@@ -112,6 +112,7 @@ class CPUMetrics(object):
             sys.add_metric([], float(raw_stats[12]) / self.ticks_per_sec)
             yield sys
 
+
 REGISTRY.register(CPUMetrics())
 
 #