diff --git a/pybtc/connector/utxo.py b/pybtc/connector/utxo.py
index ad4f944..5497911 100644
--- a/pybtc/connector/utxo.py
+++ b/pybtc/connector/utxo.py
@@ -34,7 +34,7 @@ class UTXO():
         self.outs_total = 0
 
     def set(self, outpoint, pointer, amount, address):
-        self.cached[outpoint] = [pointer, amount, address]
+        self.cached[outpoint] = (pointer, amount, address)
         self.outs_total += 1
         if pointer:
             self.last_cached_block = pointer >> 42