diff --git a/src/avalanche/peermanager.cpp b/src/avalanche/peermanager.cpp
--- a/src/avalanche/peermanager.cpp
+++ b/src/avalanche/peermanager.cpp
@@ -329,8 +329,12 @@
 
     // Release UTXOs attached to this proof.
     for (const auto &s : it->proof->getStakes()) {
-        bool deleted = utxos.erase(s.getStake().getUTXO()) > 0;
-        assert(deleted);
+        auto utxo_it = utxos.find(s.getStake().getUTXO());
+        // Make sure the UTXO has not been re-assigned to another peer before
+        // erasing.
+        if (utxo_it->second == peerid) {
+            utxos.erase(utxo_it);
+        }
     }
 
     m_unbroadcast_proofids.erase(it->proof->getId());