diff --git a/arangod/Aql/Ast.cpp b/arangod/Aql/Ast.cpp
index 0942d7db71..0b46ef5439 100644
--- a/arangod/Aql/Ast.cpp
+++ b/arangod/Aql/Ast.cpp
@@ -123,7 +123,8 @@ Ast::Ast (Query* query)
     _root(nullptr),
     _queries(),
     _writeCollections(),
-    _functionsMayAccessDocuments(false) {
+    _functionsMayAccessDocuments(false),
+    _containsTraversal(false) {
 
   TRI_ASSERT(_query != nullptr);
 
@@ -1230,6 +1231,8 @@ AstNode* Ast::createNodeTraversal (char const* vertexVarName,
 
   TRI_ASSERT(node->numMembers() == 4);
 
+  _containsTraversal = true;
+
   return node;
 }
 
@@ -1253,6 +1256,8 @@ AstNode* Ast::createNodeTraversal (char const* vertexVarName,
   node->addMember(edgeVar);
 
   TRI_ASSERT(node->numMembers() == 5);
+  
+  _containsTraversal = true;
 
   return node;
 }
@@ -1280,6 +1285,8 @@ AstNode* Ast::createNodeTraversal (char const* vertexVarName,
   node->addMember(pathVar);
 
   TRI_ASSERT(node->numMembers() == 6);
+  
+  _containsTraversal = true;
 
   return node;
 }
diff --git a/arangod/Aql/Ast.h b/arangod/Aql/Ast.h
index 28199a9ad0..ece021b579 100644
--- a/arangod/Aql/Ast.h
+++ b/arangod/Aql/Ast.h
@@ -202,6 +202,14 @@ namespace triagens {
           return _functionsMayAccessDocuments;
         }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief whether or not the query contains a traversal
+////////////////////////////////////////////////////////////////////////////////
+
+        bool containsTraversal () const {
+          return _containsTraversal;
+        }
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief convert the AST into JSON
 /// the caller is responsible for freeing the JSON later
@@ -998,6 +1006,12 @@ namespace triagens {
 
         bool                               _functionsMayAccessDocuments;
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief whether or not the query contains a traversal
+////////////////////////////////////////////////////////////////////////////////
+        
+        bool                               _containsTraversal;
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief a singleton no-op node instance
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/arangod/Aql/ExecutionPlan.cpp b/arangod/Aql/ExecutionPlan.cpp
index 193eaeae10..95a1a5aa1f 100644
--- a/arangod/Aql/ExecutionPlan.cpp
+++ b/arangod/Aql/ExecutionPlan.cpp
@@ -471,12 +471,18 @@ ModificationOptions ExecutionPlan::createModificationOptions (AstNode const* nod
     // no functions in the query can access document data...
     bool isReadWrite = false;
 
-    auto const collections = _ast->query()->collections();
+    if (_ast->containsTraversal()) {
+      // its unclear which collections the traversal will access
+      isReadWrite = true;
+    }
+    else {
+      auto const collections = _ast->query()->collections();
 
-    for (auto const& it : *(collections->collections())) {
-      if (it.second->isReadWrite) {
-        isReadWrite = true;
-        break;
+      for (auto const& it : *(collections->collections())) {
+        if (it.second->isReadWrite) {
+          isReadWrite = true;
+          break;
+        }
       }
     }
 
diff --git a/arangod/Aql/OptimizerRules.cpp b/arangod/Aql/OptimizerRules.cpp
index 76ae61832d..f3ff93980e 100644
--- a/arangod/Aql/OptimizerRules.cpp
+++ b/arangod/Aql/OptimizerRules.cpp
@@ -3686,6 +3686,12 @@ int triagens::aql::patchUpdateStatementsRule (Optimizer* opt,
           modified = true;
         }
       }
+      
+      if (type == EN::TRAVERSAL) {
+        // unclear what will be read by the traversal
+        modified = false;
+        break;
+      }
 
       dep = dep->getFirstDependency();
     }
diff --git a/js/common/modules/org/arangodb/aql/explainer.js b/js/common/modules/org/arangodb/aql/explainer.js
index d9e857270a..a4348ecdc7 100644
--- a/js/common/modules/org/arangodb/aql/explainer.js
+++ b/js/common/modules/org/arangodb/aql/explainer.js
@@ -683,10 +683,16 @@ function processQuery (query, explain) {
         }
         rc += "  " +
           keyword("IN") + " " +
-          node.minMaxDepth + "  " + annotation("/* min..maxPathDepth */") + "  " +
+          value(node.minMaxDepth) + "  " + annotation("/* min..maxPathDepth */") + "  " +
           keyword("OUTBOUND") +
-          " '" + node.vertexId + "'  " + annotation("/* Startnode */") + "  " +
-          keyword("GRAPH") +  " '" + node.graph + "'";
+          " '" + value(node.vertexId) + "'  " + annotation("/* startnode */") + "  ";
+          
+        if (Array.isArray(node.graph)) {
+          rc += node.graph.map(function(g) { return collection(g); }).join(", ");
+        }
+        else {
+          rc += keyword("GRAPH") +  " '" + value(node.graph) + "'";
+        }
 
         traversalDetails.push(node);
         if (node.hasOwnProperty('simpleExpressions')) {
diff --git a/js/server/tests/aql-multi-modify.js b/js/server/tests/aql-multi-modify.js
index 08c46a222c..0af1d82c09 100644
--- a/js/server/tests/aql-multi-modify.js
+++ b/js/server/tests/aql-multi-modify.js
@@ -73,6 +73,43 @@ function ahuacatlMultiModifySuite () {
       c3 = null;
     },
     
+    testTraversalAndModification : function () {
+      c1.insert({ _key: "1" });
+      c1.insert({ _key: "2" });
+      c1.insert({ _key: "3" });
+      c1.insert({ _key: "4" });
+      c3.insert(cn1 + "/1", cn1 + "/2", { });
+      c3.insert(cn1 + "/2", cn1 + "/3", { });
+
+      var q = "FOR v IN 1..99 OUTBOUND '" + cn1 + "/1' @@e REMOVE v._key IN @@cn";
+      var actual = AQL_EXECUTE(q, { "@cn": cn1, "@e": cn3 });
+      assertEqual([ ], actual.json);
+      assertEqual(2, actual.stats.writesExecuted);
+      assertEqual(2, c1.count());
+      assertTrue(c1.exists("1"));
+      assertTrue(c1.exists("4"));
+      assertEqual(2, c3.count());
+    },
+    
+    testTraversalAndModificationBig : function () {
+      var i;
+      for (i = 1; i <= 2010; ++i) {
+        c1.insert({ _key: String(i) });
+        if (i !== 2010) {
+          c3.insert(cn1 + "/" + String(i), cn1 + "/" + String(i + 1), { });
+        }
+      }
+
+      var q = "FOR v IN 1..2010 OUTBOUND '" + cn1 + "/1' @@e REMOVE v._key IN @@cn";
+      var actual = AQL_EXECUTE(q, { "@cn": cn1, "@e": cn3 });
+
+      assertEqual([ ], actual.json);
+      assertEqual(2009, actual.stats.writesExecuted);
+      assertEqual(1, c1.count());
+      assertTrue(c1.exists("1"));
+      assertEqual(2009, c3.count());
+    },
+    
     testTraversalAfterModification : function () {
       var q = "INSERT { _key: '1', foo: 'bar' } INTO @@cn FOR doc IN OUTBOUND 'v/1' @@e RETURN doc";
       assertQueryError(errors.ERROR_QUERY_ACCESS_AFTER_MODIFICATION.code, q, { "@cn": cn1, "@e": cn3 });