diff --git a/arangod/Aql/V8Expression.cpp b/arangod/Aql/V8Expression.cpp
index ac5b53520b..a9141b1fbd 100644
--- a/arangod/Aql/V8Expression.cpp
+++ b/arangod/Aql/V8Expression.cpp
@@ -44,10 +44,9 @@ using namespace triagens::aql;
 ////////////////////////////////////////////////////////////////////////////////
 
 V8Expression::V8Expression (v8::Isolate* isolate,
-                            v8::Persistent<v8::Function> func) 
+                            v8::Persistent<v8::Function> func)
   : isolate(isolate),
     func(func) {
-
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -76,8 +75,8 @@ AqlValue V8Expression::execute (triagens::arango::AqlTransaction* trx,
   size_t const n = vars.size();
   TRI_ASSERT(regs.size() == n); // assert same vector length
 
-  // TODO: only convert those variables to V8 that are actually used in the expression
   v8::Handle<v8::Object> values = v8::Object::New();
+
   for (size_t i = 0; i < n; ++i) {
     auto varname = vars[i]->name;
     auto reg = regs[i];
diff --git a/arangod/Aql/V8Expression.h b/arangod/Aql/V8Expression.h
index 9dd29fe889..a284cf90f7 100644
--- a/arangod/Aql/V8Expression.h
+++ b/arangod/Aql/V8Expression.h
@@ -82,10 +82,18 @@ namespace triagens {
 // --SECTION--                                                  public variables
 // -----------------------------------------------------------------------------
 
-     v8::Isolate* isolate;
+////////////////////////////////////////////////////////////////////////////////
+/// @brief the isolate used when executing and destroying the expression
+////////////////////////////////////////////////////////////////////////////////
+
+       v8::Isolate* isolate;
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief the compiled expression as a V8 function
+////////////////////////////////////////////////////////////////////////////////
+
+       v8::Persistent<v8::Function> func;
 
-     v8::Persistent<v8::Function> func;
-    
     };
 
   }