diff --git a/src/test/blobstore/implementations/onblocks/impl/DataNodeViewTest.cpp b/src/test/blobstore/implementations/onblocks/impl/DataNodeViewTest.cpp
index db4b74b7..78099121 100644
--- a/src/test/blobstore/implementations/onblocks/impl/DataNodeViewTest.cpp
+++ b/src/test/blobstore/implementations/onblocks/impl/DataNodeViewTest.cpp
@@ -20,6 +20,11 @@ using namespace blobstore::onblocks;
 
 class DataNodeViewTest: public Test {
 public:
+  //TODO Don't use InMemoryBlockStore for test cases, because it ignores flushing.
+  //     And if you for example write more than the actual block size, it still will keep that data for you,
+  //     because the next block load will just give you the same data region (and the overflow data will most
+  //     likely still be intact).
+  //     So better write a FakeBlockStore class for test cases.
   unique_ptr<BlockStore> blockStore = make_unique<InMemoryBlockStore>();
 };