diff --git a/gdb-port/commands.py b/gdb-port/commands.py
index f8cd541d82c33108bbae9b6e89d8a310793fe51b..5d141c50ec22a928e61d0c8ba11b3b34d38c5766 100644
--- a/gdb-port/commands.py
+++ b/gdb-port/commands.py
@@ -176,6 +176,8 @@ class HammerArenaDumpStats(gdb.Command):
 
 	def invoke(self, arg, from_tty):
 		args = gdb.string_to_argv(arg)
+		if len(args) != 1:
+			print("Usage: hammer-arena-dump-stats <arena address in hex>")
 		arena = args[0]
 		try:
 			arena_int = int(arena,16)
@@ -186,7 +188,6 @@ class HammerArenaDumpStats(gdb.Command):
 		print("Arena statistics for", arena, "(DETAILED_ARENA_STATISTICS:", detailed, "):")
 		HArena_p_t = gdb.lookup_type("HArena").pointer()
 		arena_gdbvalue = gdb.Value(arena_int).cast(HArena_p_t)
-		print(gdb.lookup_type("HArena").keys())
 		for key in gdb.lookup_type("HArena").keys():
 			print(key, ":", arena_gdbvalue[key])