diff --git a/arangod/RestHandler/RestImportHandler.cpp b/arangod/RestHandler/RestImportHandler.cpp
index e70d4b9614..e5cc5d4be1 100644
--- a/arangod/RestHandler/RestImportHandler.cpp
+++ b/arangod/RestHandler/RestImportHandler.cpp
@@ -246,9 +246,9 @@ int RestImportHandler::handleSingleDocument(SingleCollectionTransaction& trx,
   }
 
   try {
-    arangodb::basics::VelocyPackHelper::checkAndGetStringValue(
+    arangodb::basics::VelocyPackHelper::ensureStringValue(
         slice, StaticStrings::FromString);
-    arangodb::basics::VelocyPackHelper::checkAndGetStringValue(
+    arangodb::basics::VelocyPackHelper::ensureStringValue(
         slice, StaticStrings::ToString);
   } catch (arangodb::basics::Exception const&) {
     std::string part = VPackDumper::toString(slice);
@@ -429,20 +429,18 @@ bool RestImportHandler::createFromJson(std::string const& type) {
         continue;
       }
 
+      TRI_ASSERT(ptr != nullptr);
+      oldPtr = ptr;
+
       tmpBuilder.clear();
       if (pos != nullptr) {
         // non-empty line
         *(const_cast<char*>(pos)) = '\0';
-        TRI_ASSERT(ptr != nullptr);
-        oldPtr = ptr;
         parseVelocyPackLine(tmpBuilder, ptr, pos, success);
         ptr = pos + 1;
       } else {
         // last-line, non-empty
-        TRI_ASSERT(pos == nullptr);
-        TRI_ASSERT(ptr != nullptr);
-        oldPtr = ptr;
-        parseVelocyPackLine(tmpBuilder, ptr, success);
+        parseVelocyPackLine(tmpBuilder, ptr, end, success);
         ptr = end;
       }
 
@@ -492,13 +490,12 @@ bool RestImportHandler::createFromJson(std::string const& type) {
       return false;
     }
 
-    VPackValueLength const n = documents.length();
     VPackBuilder lineBuilder;
-    for (VPackValueLength i = 0; i < n; ++i) {
-      VPackSlice const slice = documents.at(i);
+    VPackArrayIterator it(documents);
 
-      res = handleSingleDocument(trx, lineBuilder, result, babies, slice, isEdgeCollection,
-                                 static_cast<size_t>(i + 1));
+    while (it.valid()) {
+      res = handleSingleDocument(trx, lineBuilder, result, babies, it.value(), isEdgeCollection,
+                                 static_cast<size_t>(it.index() + 1));
 
       if (res.fail()) {
         if (complete) {
@@ -508,6 +505,8 @@ bool RestImportHandler::createFromJson(std::string const& type) {
 
         res = TRI_ERROR_NO_ERROR;
       }
+
+      it.next();
     }
   }
 
@@ -597,14 +596,12 @@ bool RestImportHandler::createFromVPack(std::string const& type) {
     return false;
   }
 
-  VPackValueLength const n = documents.length();
-
   VPackBuilder lineBuilder;
-  for (VPackValueLength i = 0; i < n; ++i) {
-    VPackSlice const slice = documents.at(i);
 
-    res = handleSingleDocument(trx, lineBuilder, result, babies, slice, isEdgeCollection,
-                               static_cast<size_t>(i + 1));
+  VPackArrayIterator it(documents);
+  while (it.valid()) {
+    res = handleSingleDocument(trx, lineBuilder, result, babies, it.value(), isEdgeCollection,
+                               static_cast<size_t>(it.index() + 1));
 
     if (res.fail()) {
       if (complete) {
@@ -614,6 +611,8 @@ bool RestImportHandler::createFromVPack(std::string const& type) {
 
       res = TRI_ERROR_NO_ERROR;
     }
+
+    it.next();
   }
 
   babies.close();
@@ -1042,28 +1041,12 @@ void RestImportHandler::generateDocumentsCreated(
 /// @brief parse a single document line
 ////////////////////////////////////////////////////////////////////////////////
 
-void RestImportHandler::parseVelocyPackLine(
-    VPackBuilder& builder,
-    std::string const& line, bool& success) {
-  try {
-    success = true;
-    VPackParser parser(builder);
-    parser.parse(line);
-  } catch (VPackException const&) {
-    success = false;
-  }
-}
-
-////////////////////////////////////////////////////////////////////////////////
-/// @brief parse a single document line
-////////////////////////////////////////////////////////////////////////////////
-
 void RestImportHandler::parseVelocyPackLine(VPackBuilder& builder,
     char const* start, char const* end, bool& success) {
   try {
     success = true;
     VPackParser parser(builder);
-    parser.parse(start,std::distance(start, end));
+    parser.parse(start, std::distance(start, end));
   } catch (std::exception const&) {
     // The line is invalid and could not be transformed into a string
     success = false;
diff --git a/arangod/RestHandler/RestImportHandler.h b/arangod/RestHandler/RestImportHandler.h
index c72f98ffd0..4ae20b0511 100644
--- a/arangod/RestHandler/RestImportHandler.h
+++ b/arangod/RestHandler/RestImportHandler.h
@@ -141,12 +141,6 @@ class RestImportHandler : public RestVocbaseBaseHandler {
   /// @brief parses a string
   //////////////////////////////////////////////////////////////////////////////
 
-  void parseVelocyPackLine(VPackBuilder&, std::string const&, bool&);
-
-  //////////////////////////////////////////////////////////////////////////////
-  /// @brief parses a string
-  //////////////////////////////////////////////////////////////////////////////
-
   void parseVelocyPackLine(VPackBuilder&, char const*, char const*, bool&);
 
   //////////////////////////////////////////////////////////////////////////////
diff --git a/arangod/Transaction/Methods.cpp b/arangod/Transaction/Methods.cpp
index 24b43a1475..e291a458f6 100644
--- a/arangod/Transaction/Methods.cpp
+++ b/arangod/Transaction/Methods.cpp
@@ -675,7 +675,7 @@ void transaction::Methods::buildDocumentIdentity(
     LogicalCollection* collection, VPackBuilder& builder, TRI_voc_cid_t cid,
     StringRef const& key, TRI_voc_rid_t rid, TRI_voc_rid_t oldRid,
     ManagedDocumentResult const* oldDoc, ManagedDocumentResult const* newDoc) {
-  std::string temp;
+  std::string temp; // TODO: pass a string into this function
   temp.reserve(64);
 
   if (_state->isRunningInCluster()) {
diff --git a/lib/Basics/VelocyPackHelper.cpp b/lib/Basics/VelocyPackHelper.cpp
index 3229a9545d..27638daf06 100644
--- a/lib/Basics/VelocyPackHelper.cpp
+++ b/lib/Basics/VelocyPackHelper.cpp
@@ -488,6 +488,20 @@ std::string VelocyPackHelper::checkAndGetStringValue(VPackSlice const& slice,
   return sub.copyString();
 }
 
+void VelocyPackHelper::ensureStringValue(VPackSlice const& slice,
+                                         std::string const& name) {
+  TRI_ASSERT(slice.isObject());
+  if (!slice.hasKey(name)) {
+    std::string msg = "The attribute '" + name + "' was not found.";
+    THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_BAD_PARAMETER, msg);
+  }
+  VPackSlice const sub = slice.get(name);
+  if (!sub.isString()) {
+    std::string msg = "The attribute '" + name + "' is not a string.";
+    THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_BAD_PARAMETER, msg);
+  }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief returns a string value, or the default value if it is not a string
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/lib/Basics/VelocyPackHelper.h b/lib/Basics/VelocyPackHelper.h
index e3a128000f..7fc42c6e37 100644
--- a/lib/Basics/VelocyPackHelper.h
+++ b/lib/Basics/VelocyPackHelper.h
@@ -281,9 +281,16 @@ class VelocyPackHelper {
   //////////////////////////////////////////////////////////////////////////////
 
   static std::string checkAndGetStringValue(VPackSlice const&, char const*);
+  
+  //////////////////////////////////////////////////////////////////////////////
+  /// @brief ensures a sub-element is of type string
+  //////////////////////////////////////////////////////////////////////////////
 
   static std::string checkAndGetStringValue(VPackSlice const&,
                                             std::string const&);
+  
+  static void ensureStringValue(VPackSlice const&,
+                                std::string const&);
 
   //////////////////////////////////////////////////////////////////////////////
   /// @brief returns a Numeric sub-element, or throws if <name> does not exist