diff --git a/src/qt/walletmodel.cpp b/src/qt/walletmodel.cpp
index 78bc17062..6f3e3b0aa 100644
--- a/src/qt/walletmodel.cpp
+++ b/src/qt/walletmodel.cpp
@@ -502,6 +502,7 @@ void WalletModel::listCoins(std::map<QString, std::vector<COutput> >& mapCoins)
     std::vector<COutput> vCoins;
     wallet->AvailableCoins(vCoins);
 
+    LOCK(wallet->cs_wallet); // ListLockedCoins, mapWallet
     std::vector<COutPoint> vLockedCoins;
     wallet->ListLockedCoins(vLockedCoins);