diff --git a/changelog.d/3690.misc b/changelog.d/3690.misc
new file mode 100644
index 0000000000000000000000000000000000000000..710add02433d1a97b4677e20f66e9d024b9e1753
--- /dev/null
+++ b/changelog.d/3690.misc
@@ -0,0 +1 @@
+Rename MAU prometheus metrics
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index 37a9b126a5c14925365b25b7bfd2b4ae38772760..a98bb506e5fb4cef01133cdf0dcd4ae493d31d6f 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -303,8 +303,8 @@ class SynapseHomeServer(HomeServer):
 
 
 # Gauges to expose monthly active user control metrics
-current_mau_gauge = Gauge("synapse_admin_current_mau", "Current MAU")
-max_mau_value_gauge = Gauge("synapse_admin_max_mau_value", "MAU Limit")
+current_mau_gauge = Gauge("synapse_admin_mau:current", "Current MAU")
+max_mau_gauge = Gauge("synapse_admin_mau:max", "MAU Limit")
 
 
 def setup(config_options):
@@ -532,7 +532,7 @@ def run(hs):
         if hs.config.limit_usage_by_mau:
             count = yield hs.get_datastore().get_monthly_active_count()
         current_mau_gauge.set(float(count))
-        max_mau_value_gauge.set(float(hs.config.max_mau_value))
+        max_mau_gauge.set(float(hs.config.max_mau_value))
 
     hs.get_datastore().initialise_reserved_users(
         hs.config.mau_limits_reserved_threepids