diff --git a/implementations/onblocks/datatreestore/DataTree.cpp b/implementations/onblocks/datatreestore/DataTree.cpp
index 366d5f50..3326275a 100644
--- a/implementations/onblocks/datatreestore/DataTree.cpp
+++ b/implementations/onblocks/datatreestore/DataTree.cpp
@@ -160,6 +160,10 @@ uint32_t DataTree::_numLeaves(const DataNode &node) const {
 void DataTree::traverseLeaves(uint32_t beginIndex, uint32_t endIndex, function<void (DataLeafNode*, uint32_t)> func) {
   unique_lock<shared_mutex> lock(_mutex); //TODO Only lock when resizing. Otherwise parallel read/write to a blob is not possible!
   ASSERT(beginIndex <= endIndex, "Invalid parameters");
+  if (0 == endIndex) {
+    // In this case the utils::ceilLog(_, endIndex) below would fail
+    return;
+  }
 
   uint8_t neededTreeDepth = utils::ceilLog(_nodeStore->layout().maxChildrenPerInnerNode(), endIndex);
   uint32_t numLeaves = this->_numLeaves(*_rootNode); // TODO Querying the size causes a tree traversal down to the leaves. Possible without querying the size?