diff --git a/packages/caver-klay/caver-klay-accounts/src/index.js b/packages/caver-klay/caver-klay-accounts/src/index.js
index 219acd23..493b400e 100644
--- a/packages/caver-klay/caver-klay-accounts/src/index.js
+++ b/packages/caver-klay/caver-klay-accounts/src/index.js
@@ -1393,7 +1393,8 @@ Accounts.prototype.decrypt = function(v3Keystore, password, nonStrict) {
         throw new Error('No password given.')
     }
 
-    const json = _.isObject(v3Keystore) ? v3Keystore : JSON.parse(nonStrict ? v3Keystore.toLowerCase() : v3Keystore)
+    // To deep copy an object, using JSON.parse and JSON.stringify (object -> string -> object)
+    const json = _.isObject(v3Keystore) ? _.cloneDeep(v3Keystore) : JSON.parse(nonStrict ? v3Keystore.toLowerCase() : v3Keystore)
 
     if (json.version !== 3 && json.version !== 4) {
         console.warn('This is not a V3 or V4 wallet.')
diff --git a/packages/caver-wallet/src/keyring/keyringFactory.js b/packages/caver-wallet/src/keyring/keyringFactory.js
index d3a62875..c80a14cc 100644
--- a/packages/caver-wallet/src/keyring/keyringFactory.js
+++ b/packages/caver-wallet/src/keyring/keyringFactory.js
@@ -209,7 +209,8 @@ class KeyringFactory {
      * @return {AbstractKeyring}
      */
     static decrypt(keystore, password) {
-        const json = _.isObject(keystore) ? keystore : JSON.parse(keystore)
+        // To deep copy an object, using JSON.parse and JSON.stringify (object -> string -> object)
+        const json = _.isObject(keystore) ? _.cloneDeep(keystore) : JSON.parse(keystore)
 
         if (json.version !== 3 && json.version !== 4) console.warn('This is not a V3 or V4 wallet.')
 
diff --git a/test/packages/caver.klay.accounts.js b/test/packages/caver.klay.accounts.js
index 46f72762..81087075 100644
--- a/test/packages/caver.klay.accounts.js
+++ b/test/packages/caver.klay.accounts.js
@@ -3531,6 +3531,7 @@ describe('caver.klay.accounts.decrypt', () => {
             const result = caver.klay.accounts.decrypt(keystoreJsonV3, password)
 
             isAccount(result, { keys: expectedAccount.keys, address: expectedAccount.address })
+            expect(keystoreJsonV3.crypto).not.to.be.undefined
         }).timeout(50000)
     })
 
diff --git a/test/packages/caver.wallet.keyring.js b/test/packages/caver.wallet.keyring.js
index 90ac261b..dabe2b81 100644
--- a/test/packages/caver.wallet.keyring.js
+++ b/test/packages/caver.wallet.keyring.js
@@ -789,6 +789,7 @@ describe('caver.wallet.keyring.decrypt', () => {
             const result = caver.wallet.keyring.decrypt(keystoreJsonV3, password)
 
             validateKeyring(result, { keys: expectedAccount.keys, address: expectedAccount.address })
+            expect(keystoreJsonV3.crypto).not.to.be.undefined
         })
     })
 })