diff --git a/changelog.d/4110.misc b/changelog.d/4110.misc
new file mode 100644
index 0000000000..a50327ae34
--- /dev/null
+++ b/changelog.d/4110.misc
@@ -0,0 +1 @@
+Fix `synapse_replication_tcp_protocol_*_commands` metric label to be full command name, rather than just the first character
diff --git a/synapse/replication/tcp/protocol.py b/synapse/replication/tcp/protocol.py
index 5dc7b3fffc..0b3fe6cbf5 100644
--- a/synapse/replication/tcp/protocol.py
+++ b/synapse/replication/tcp/protocol.py
@@ -656,7 +656,7 @@ tcp_inbound_commands = LaterGauge(
     "",
     ["command", "name"],
     lambda: {
-        (k[0], p.name,): count
+        (k, p.name,): count
         for p in connected_connections
         for k, count in iteritems(p.inbound_commands_counter)
     },
@@ -667,7 +667,7 @@ tcp_outbound_commands = LaterGauge(
     "",
     ["command", "name"],
     lambda: {
-        (k[0], p.name,): count
+        (k, p.name,): count
         for p in connected_connections
         for k, count in iteritems(p.outbound_commands_counter)
     },