diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index a5db987bbb..d7694f44d9 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -25,6 +25,7 @@
 #include <script/script.h>
 #include <script/sign.h>
 #include <script/signingprovider.h>
+#include <support/cleanse.h>
 #include <txmempool.h>
 #include <util/bip32.h>
 #include <util/check.h>
@@ -5583,7 +5584,10 @@ bool CWallet::Lock(bool fAllowMixing)
 
     if(!fAllowMixing) {
         LOCK(cs_wallet);
-        vMasterKey.clear();
+        if (!vMasterKey.empty()) {
+            memory_cleanse(vMasterKey.data(), vMasterKey.size() * sizeof(decltype(vMasterKey)::value_type));
+            vMasterKey.clear();
+        }
     }
 
     fOnlyMixingAllowed = fAllowMixing;