diff --git a/silkaj/money.py b/silkaj/money.py
index 3c41d06dbac2eec9625e3567c1b4241450dc56d9..c324d36eb056ad7b0197347dbbd959e7ccacd271 100644
--- a/silkaj/money.py
+++ b/silkaj/money.py
@@ -48,6 +48,12 @@ async def cmd_amount(ctx, pubkeys):
         checked_pubkeys = list()
         for pubkey in pubkeys:
             pubkey = check_public_key(pubkey, True)
+            if pubkey in checked_pubkeys:
+                message_exit(
+                    "Error : pubkey {0} was specified many times".format(
+                        pubkey_with_checksum(pubkey)
+                    )
+                )
             checked_pubkeys.append(pubkey)
             if not pubkey:
                 return