diff --git a/arangod/Utils/Transaction.h b/arangod/Utils/Transaction.h
index 91689736b7..14ce4c8ae1 100644
--- a/arangod/Utils/Transaction.h
+++ b/arangod/Utils/Transaction.h
@@ -423,7 +423,6 @@ namespace triagens {
           int res = this->lock(trxCollection, TRI_TRANSACTION_READ);
 
           if (res != TRI_ERROR_NO_ERROR) {
-            this->unlock(trxCollection, TRI_TRANSACTION_READ);
             TRI_FreeBarrier(*barrier);
             *barrier = 0;
             return res;
@@ -486,7 +485,6 @@ namespace triagens {
           int res = this->lock(trxCollection, TRI_TRANSACTION_READ);
           
           if (res != TRI_ERROR_NO_ERROR) {
-            this->unlock(trxCollection, TRI_TRANSACTION_READ);
             return res;
           }
 
@@ -533,7 +531,6 @@ namespace triagens {
           int res = this->lock(trxCollection, TRI_TRANSACTION_READ);
 
           if (res != TRI_ERROR_NO_ERROR) {
-            this->unlock(trxCollection, TRI_TRANSACTION_READ);
             return res;
           }
 
@@ -770,6 +767,7 @@ namespace triagens {
 
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief truncate a collection
+/// the caller must make sure a barrier is held
 ////////////////////////////////////////////////////////////////////////////////
 
         int removeAll (TRI_transaction_collection_t* const trxCollection,
@@ -777,25 +775,25 @@ namespace triagens {
 
           vector<string> ids;
           
-          int res = readAll(trxCollection, ids);
+          TRI_primary_collection_t* primary = primaryCollection(trxCollection);
+          
+          // WRITE-LOCK START
+          int res = this->lock(trxCollection, TRI_TRANSACTION_WRITE);
+          
+          if (res != TRI_ERROR_NO_ERROR) {
+            return res;
+          }
+          
+          res = readAll(trxCollection, ids);
 
           if (res != TRI_ERROR_NO_ERROR) {
+            this->unlock(trxCollection, TRI_TRANSACTION_WRITE);
             return res;
           }
 
           TRI_doc_update_policy_t updatePolicy;
           TRI_InitUpdatePolicy(&updatePolicy, TRI_DOC_UPDATE_LAST_WRITE, 0, NULL);
-
-          size_t n = ids.size();
-
-          TRI_primary_collection_t* primary = primaryCollection(trxCollection);
-
-          // WRITE-LOCK START
-          res = this->lock(trxCollection, TRI_TRANSACTION_WRITE);
-
-          if (res != TRI_ERROR_NO_ERROR) {
-            return res;
-          }
+          const size_t n = ids.size();
 
           for (size_t i = 0; i < n; ++i) {
             const string& id = ids[i];
diff --git a/arangod/V8Server/v8-vocbase.cpp b/arangod/V8Server/v8-vocbase.cpp
index 6b7163c3fa..e4fe308513 100644
--- a/arangod/V8Server/v8-vocbase.cpp
+++ b/arangod/V8Server/v8-vocbase.cpp
@@ -5455,18 +5455,26 @@ static v8::Handle<v8::Value> JS_TruncateVocbaseCol (v8::Arguments const& argv) {
   if (col == 0) {
     TRI_V8_EXCEPTION_INTERNAL(scope, "cannot extract collection");
   }
-
+  
   CollectionNameResolver resolver(col->_vocbase);
   SingleCollectionWriteTransaction<EmbeddableTransaction<V8TransactionContext>, UINT64_MAX> trx(col->_vocbase, resolver, col->_cid);
   int res = trx.begin();
-
+  
   if (res != TRI_ERROR_NO_ERROR) {
     TRI_V8_EXCEPTION_MESSAGE(scope, res, "cannot truncate collection");
   }
+  
+  TRI_barrier_t* barrier = TRI_CreateBarrierElement(&(trx.primaryCollection()->_barrierList));
+
+  if (barrier == 0) {
+    TRI_V8_EXCEPTION_MEMORY(scope);
+  }
 
   res = trx.truncate(forceSync);
   res = trx.finish(res);
 
+  TRI_FreeBarrier(barrier);
+
   if (res != TRI_ERROR_NO_ERROR) {
     TRI_V8_EXCEPTION_MESSAGE(scope, res, "cannot truncate collection");
   }