diff --git a/rskj-core/src/main/java/co/rsk/db/ContractDetailsImpl.java b/rskj-core/src/main/java/co/rsk/db/ContractDetailsImpl.java
index d19daba7420..984df137770 100644
--- a/rskj-core/src/main/java/co/rsk/db/ContractDetailsImpl.java
+++ b/rskj-core/src/main/java/co/rsk/db/ContractDetailsImpl.java
@@ -384,6 +384,12 @@ public boolean isNullObject() {
         return (code==null || code.length==0) && keys.isEmpty();
     }
 
+    @Override
+    public void mergeStore(ContractDetails storeContractDetails) {
+        ((ContractDetailsImpl) storeContractDetails).getTrie().copyTo(((TrieImpl)this.trie).getStore());
+        checkExternalStorage();
+    }
+
     public Trie getTrie() {
         return this.trie;
     }
@@ -401,7 +407,7 @@ private void removeKey(byte[] key) {
     }
 
     private void checkExternalStorage() {
-        this.externalStorage = (keys.size() > memoryStorageLimit) || this.externalStorage;
+        this.externalStorage = true;
     }
 
     private String getDataSourceName() {
diff --git a/rskj-core/src/main/java/co/rsk/db/RepositoryImpl.java b/rskj-core/src/main/java/co/rsk/db/RepositoryImpl.java
index b8a1cdaa93a..e72e7396aac 100644
--- a/rskj-core/src/main/java/co/rsk/db/RepositoryImpl.java
+++ b/rskj-core/src/main/java/co/rsk/db/RepositoryImpl.java
@@ -97,7 +97,7 @@ public synchronized AccountState createAccount(RskAddress addr) {
                 null,
                 trieStoreFactory,
                 memoryStorageLimit
-        ));
+        ), null);
         return accountState;
     }
 
@@ -181,7 +181,7 @@ public synchronized void saveCode(RskAddress addr, byte[] code) {
         details.setCode(code);
         accountState.setCodeHash(Keccak256Helper.keccak256(code));
 
-        updateContractDetails(addr, details);
+        updateContractDetails(addr, details, null);
         updateAccountState(addr, accountState);
     }
 
@@ -217,7 +217,7 @@ public synchronized void addStorageRow(RskAddress addr, DataWord key, DataWord v
 
         details.put(key, value);
 
-        updateContractDetails(addr, details);
+        updateContractDetails(addr, details, null);
     }
 
     @Override
@@ -231,7 +231,7 @@ public synchronized void addStorageBytes(RskAddress addr, DataWord key, byte[] v
 
         details.putBytes(key, value);
 
-        updateContractDetails(addr, details);
+        updateContractDetails(addr, details, null);
     }
 
     @Override
@@ -366,8 +366,9 @@ public synchronized void updateBatch(Map<RskAddress, AccountState> stateCache,
                 }
 
                 contractDetails = contractDetailsCache.getOriginalContractDetails();
+                ContractDetails storeContractDetails = detailsDataStore.get(addr);
 
-                updateContractDetails(addr, contractDetails);
+                updateContractDetails(addr, contractDetails, storeContractDetails);
 
                 if (!Arrays.equals(accountState.getCodeHash(), EMPTY_TRIE_HASH)) {
                     accountState.setStateRoot(contractDetails.getStorageHash());
@@ -423,7 +424,12 @@ public synchronized DetailsDataStore getDetailsDataStore() {
     }
 
     @Override
-    public synchronized void updateContractDetails(RskAddress addr, final ContractDetails contractDetails) {
+    public synchronized void updateContractDetails(RskAddress addr,
+            final ContractDetails contractDetails,
+            final ContractDetails storeContractDetails) {
+        if (storeContractDetails != null) {
+            contractDetails.mergeStore(storeContractDetails);
+        }
         detailsDataStore.update(addr, contractDetails);
     }
 
diff --git a/rskj-core/src/main/java/org/ethereum/core/Repository.java b/rskj-core/src/main/java/org/ethereum/core/Repository.java
index c3601bde911..14ef9555c29 100644
--- a/rskj-core/src/main/java/org/ethereum/core/Repository.java
+++ b/rskj-core/src/main/java/org/ethereum/core/Repository.java
@@ -199,7 +199,10 @@ void loadAccount(RskAddress addr,
 
     DetailsDataStore getDetailsDataStore();
 
-    void updateContractDetails(RskAddress addr, final ContractDetails contractDetails);
+    void updateContractDetails(
+            RskAddress addr,
+            final ContractDetails contractDetails,
+            ContractDetails storeContractDetails);
 
     void updateAccountState(RskAddress addr, AccountState accountState);
 
diff --git a/rskj-core/src/main/java/org/ethereum/core/genesis/BlockChainLoader.java b/rskj-core/src/main/java/org/ethereum/core/genesis/BlockChainLoader.java
index 8d80e9f99bb..553c1ca63ae 100644
--- a/rskj-core/src/main/java/org/ethereum/core/genesis/BlockChainLoader.java
+++ b/rskj-core/src/main/java/org/ethereum/core/genesis/BlockChainLoader.java
@@ -130,7 +130,8 @@ public BlockChainImpl loadBlockchain() {
                 accountState.setNonce(initialAddressState.getAccountState().getNonce());
 
                 if (initialAddressState.getContractDetails()!=null) {
-                    repository.updateContractDetails(addr, initialAddressState.getContractDetails());
+                    repository.updateContractDetails(addr, initialAddressState.getContractDetails(),
+                                                     null);
                     accountState.setStateRoot(initialAddressState.getAccountState().getStateRoot());
                     accountState.setCodeHash(initialAddressState.getAccountState().getCodeHash());
                 }
diff --git a/rskj-core/src/main/java/org/ethereum/db/ContractDetails.java b/rskj-core/src/main/java/org/ethereum/db/ContractDetails.java
index e4edaf785bc..bcc406f7a34 100644
--- a/rskj-core/src/main/java/org/ethereum/db/ContractDetails.java
+++ b/rskj-core/src/main/java/org/ethereum/db/ContractDetails.java
@@ -78,4 +78,6 @@ public interface ContractDetails {
     ContractDetails getSnapshotTo(byte[] hash);
 
     boolean isNullObject();
+
+    void mergeStore(ContractDetails storeContractDetails);
 }
diff --git a/rskj-core/src/main/java/org/ethereum/db/ContractDetailsCacheImpl.java b/rskj-core/src/main/java/org/ethereum/db/ContractDetailsCacheImpl.java
index 4b1b4db37fc..bb5f0b65338 100644
--- a/rskj-core/src/main/java/org/ethereum/db/ContractDetailsCacheImpl.java
+++ b/rskj-core/src/main/java/org/ethereum/db/ContractDetailsCacheImpl.java
@@ -305,6 +305,11 @@ public boolean isNullObject() {
         return origContract.isNullObject() && (MapUtils.isEmpty(storage));
     }
 
+    @Override
+    public void mergeStore(ContractDetails storeContractDetails) {
+        throw new UnsupportedOperationException("No merge option during cache state");
+    }
+
     public ContractDetails getOriginalContractDetails() {
         return this.origContract;
     }
diff --git a/rskj-core/src/main/java/org/ethereum/vm/program/Storage.java b/rskj-core/src/main/java/org/ethereum/vm/program/Storage.java
index 01770e8ab6c..2b41aed30a9 100644
--- a/rskj-core/src/main/java/org/ethereum/vm/program/Storage.java
+++ b/rskj-core/src/main/java/org/ethereum/vm/program/Storage.java
@@ -245,7 +245,10 @@ public DetailsDataStore getDetailsDataStore() {
     }
 
     @Override
-    public void updateContractDetails(RskAddress addr, ContractDetails contractDetails) {
+    public void updateContractDetails(
+            RskAddress addr,
+            ContractDetails contractDetails,
+            ContractDetails storeContractDetails) {
         throw new UnsupportedOperationException();
     }
 
diff --git a/rskj-core/src/test/java/co/rsk/core/NetworkStateExporterTest.java b/rskj-core/src/test/java/co/rsk/core/NetworkStateExporterTest.java
index db7eeda1858..402a2df4c81 100644
--- a/rskj-core/src/test/java/co/rsk/core/NetworkStateExporterTest.java
+++ b/rskj-core/src/test/java/co/rsk/core/NetworkStateExporterTest.java
@@ -135,7 +135,7 @@ public void testContracts() throws Exception {
         contractDetails.setCode(new byte[] {1, 2, 3, 4});
         contractDetails.put(DataWord.ZERO, DataWord.ONE);
         contractDetails.putBytes(DataWord.ONE, new byte[] {5, 6, 7, 8});
-        repository.updateContractDetails(addr1, contractDetails);
+        repository.updateContractDetails(addr1, contractDetails, null);
         AccountState accountState = repository.getAccountState(addr1);
         accountState.setStateRoot(contractDetails.getStorageHash());
         repository.updateAccountState(addr1, accountState);