diff --git a/src/CryDevice.cpp b/src/CryDevice.cpp
index 6c03d193..16f116d7 100644
--- a/src/CryDevice.cpp
+++ b/src/CryDevice.cpp
@@ -28,7 +28,9 @@ using blobstore::onblocks::BlobStoreOnBlocks;
 using blobstore::onblocks::BlobOnBlocks;
 using blockstore::caching::CachingBlockStore;
 using cpputils::unique_ref;
+using cpputils::make_unique_ref;
 using boost::optional;
+using boost::none;
 
 namespace bf = boost::filesystem;
 
@@ -71,44 +73,48 @@ unique_ptr<fspp::Node> CryDevice::Load(const bf::path &path) {
 
   if (path.parent_path().empty()) {
     //We are asked to load the root directory '/'.
-    return make_unique<CryDir>(this, nullptr, _rootKey);
+    return make_unique<CryDir>(this, none, _rootKey);
   }
   auto parent = LoadDirBlob(path.parent_path());
-  auto entry = parent->GetChild(path.filename().native());
+  if (parent == none) {
+    //TODO Return correct fuse error
+    return nullptr;
+  }
+  auto entry = (*parent)->GetChild(path.filename().native());
 
   if (entry.type == fspp::Dir::EntryType::DIR) {
-    return make_unique<CryDir>(this, std::move(parent), entry.key);
+    return make_unique<CryDir>(this, std::move(*parent), entry.key);
   } else if (entry.type == fspp::Dir::EntryType::FILE) {
-    return make_unique<CryFile>(this, std::move(parent), entry.key);
+    return make_unique<CryFile>(this, std::move(*parent), entry.key);
   } else if (entry.type == fspp::Dir::EntryType::SYMLINK) {
-	return make_unique<CrySymlink>(this, std::move(parent), entry.key);
+	return make_unique<CrySymlink>(this, std::move(*parent), entry.key);
   } else {
     throw FuseErrnoException(EIO);
   }
 }
 
-unique_ptr<DirBlob> CryDevice::LoadDirBlob(const bf::path &path) {
+optional<unique_ref<DirBlob>> CryDevice::LoadDirBlob(const bf::path &path) {
   auto currentBlob = _blobStore->load(_rootKey);
-  if(!currentBlob) {
+  if(currentBlob == none) {
     //TODO Return correct fuse error
-    return nullptr;
+    return none;
   }
 
   for (const bf::path &component : path.relative_path()) {
     //TODO Check whether the next path component is a dir.
     //     Right now, an assertion in DirBlob constructor will fail if it isn't.
     //     But fuse should rather return the correct error code.
-    unique_ptr<DirBlob> currentDir = make_unique<DirBlob>(std::move(*currentBlob), this);
+    unique_ref<DirBlob> currentDir = make_unique_ref<DirBlob>(std::move(*currentBlob), this);
 
     Key childKey = currentDir->GetChild(component.c_str()).key;
     currentBlob = _blobStore->load(childKey);
-    if(!currentBlob) {
+    if(currentBlob == none) {
       //TODO Return correct fuse error
-      return nullptr;
+      return none;
     }
   }
 
-  return make_unique<DirBlob>(std::move(*currentBlob), this);
+  return make_unique_ref<DirBlob>(std::move(*currentBlob), this);
 }
 
 void CryDevice::statfs(const bf::path &path, struct statvfs *fsstat) {
diff --git a/src/CryDevice.h b/src/CryDevice.h
index 0865d6a2..0bbf3e0b 100644
--- a/src/CryDevice.h
+++ b/src/CryDevice.h
@@ -31,7 +31,7 @@ public:
 
   std::unique_ptr<fspp::Node> Load(const boost::filesystem::path &path) override;
 
-  std::unique_ptr<DirBlob> LoadDirBlob(const boost::filesystem::path &path);
+  boost::optional<cpputils::unique_ref<DirBlob>> LoadDirBlob(const boost::filesystem::path &path);
 
 private:
   blockstore::Key GetOrCreateRootKey(CryConfig *config);
diff --git a/src/CryDir.cpp b/src/CryDir.cpp
index 49da7b36..296f557c 100644
--- a/src/CryDir.cpp
+++ b/src/CryDir.cpp
@@ -29,7 +29,7 @@ using boost::none;
 
 namespace cryfs {
 
-CryDir::CryDir(CryDevice *device, unique_ptr<DirBlob> parent, const Key &key)
+CryDir::CryDir(CryDevice *device, boost::optional<unique_ref<DirBlob>> parent, const Key &key)
 : CryNode(device, std::move(parent), key) {
 }
 
diff --git a/src/CryDir.h b/src/CryDir.h
index d141becf..34b61e3b 100644
--- a/src/CryDir.h
+++ b/src/CryDir.h
@@ -10,7 +10,7 @@ namespace cryfs {
 
 class CryDir: public fspp::Dir, CryNode {
 public:
-  CryDir(CryDevice *device, std::unique_ptr<DirBlob> parent, const blockstore::Key &key);
+  CryDir(CryDevice *device, boost::optional<cpputils::unique_ref<DirBlob>> parent, const blockstore::Key &key);
   virtual ~CryDir();
 
   //TODO return type variance to CryFile/CryDir?
diff --git a/src/CryFile.cpp b/src/CryFile.cpp
index bc75d2dc..da3cf853 100644
--- a/src/CryFile.cpp
+++ b/src/CryFile.cpp
@@ -16,10 +16,12 @@ using std::make_unique;
 
 using blockstore::Key;
 using boost::none;
+using cpputils::unique_ref;
+using cpputils::make_unique_ref;
 
 namespace cryfs {
 
-CryFile::CryFile(CryDevice *device, unique_ptr<DirBlob> parent, const Key &key)
+CryFile::CryFile(CryDevice *device, unique_ref<DirBlob> parent, const Key &key)
 : CryNode(device, std::move(parent), key) {
 }
 
@@ -29,7 +31,7 @@ CryFile::~CryFile() {
 unique_ptr<fspp::OpenFile> CryFile::open(int flags) const {
   auto blob = LoadBlob();
   assert(blob != none);
-  return make_unique<CryOpenFile>(make_unique<FileBlob>(std::move(*blob)));
+  return make_unique<CryOpenFile>(make_unique_ref<FileBlob>(std::move(*blob)));
 }
 
 void CryFile::truncate(off_t size) const {
diff --git a/src/CryFile.h b/src/CryFile.h
index b25334c7..7fef5820 100644
--- a/src/CryFile.h
+++ b/src/CryFile.h
@@ -11,7 +11,7 @@ namespace cryfs {
 
 class CryFile: public fspp::File, CryNode {
 public:
-  CryFile(CryDevice *device, std::unique_ptr<DirBlob> parent, const blockstore::Key &key);
+  CryFile(CryDevice *device, cpputils::unique_ref<DirBlob> parent, const blockstore::Key &key);
   virtual ~CryFile();
 
   std::unique_ptr<fspp::OpenFile> open(int flags) const override;
diff --git a/src/CryNode.cpp b/src/CryNode.cpp
index b12b021a..289023da 100644
--- a/src/CryNode.cpp
+++ b/src/CryNode.cpp
@@ -16,6 +16,7 @@ using blobstore::Blob;
 using cpputils::dynamic_pointer_move;
 using cpputils::unique_ref;
 using boost::optional;
+using boost::none;
 
 //TODO Get rid of this in favor of an exception hierarchy
 using fspp::fuse::CHECK_RETVAL;
@@ -23,7 +24,7 @@ using fspp::fuse::FuseErrnoException;
 
 namespace cryfs {
 
-CryNode::CryNode(CryDevice *device, unique_ptr<DirBlob> parent, const Key &key)
+CryNode::CryNode(CryDevice *device, optional<unique_ref<DirBlob>> parent, const Key &key)
 : _device(device),
   _parent(std::move(parent)),
   _key(key) {
@@ -39,16 +40,25 @@ void CryNode::access(int mask) const {
 }
 
 void CryNode::rename(const bf::path &to) {
+  if (_parent == none) {
+    //We are the root direcory.
+    //TODO What should we do?
+    throw FuseErrnoException(EIO);
+  }
   //TODO More efficient implementation possible: directly rename when it's actually not moved to a different directory
   //     It's also quite ugly code because in the parent==targetDir case, it depends on _parent not overriding the changes made by targetDir.
-  auto old = _parent->GetChild(_key);
+  auto old = (*_parent)->GetChild(_key);
   auto mode = old.mode;
   auto uid = old.uid;
   auto gid = old.gid;
-  _parent->RemoveChild(_key);
-  _parent->flush();
+  (*_parent)->RemoveChild(_key);
+  (*_parent)->flush();
   auto targetDir = _device->LoadDirBlob(to.parent_path());
-  targetDir->AddChild(to.filename().native(), _key, getType(), mode, uid, gid);
+  if (targetDir == none) {
+    //TODO Return correct fuse error
+    throw FuseErrnoException(ENOSPC);
+  }
+  (*targetDir)->AddChild(to.filename().native(), _key, getType(), mode, uid, gid);
 }
 
 void CryNode::utimens(const timespec times[2]) {
@@ -57,7 +67,13 @@ void CryNode::utimens(const timespec times[2]) {
 }
 
 void CryNode::remove() {
-  _parent->RemoveChild(_key);
+  //TODO Instead of all these if-else and having _parent being an optional, we could also introduce a CryRootDir which inherits from fspp::Dir.
+  if (_parent == none) {
+    //We are the root direcory.
+    //TODO What should we do?
+    throw FuseErrnoException(EIO);
+  }
+  (*_parent)->RemoveChild(_key);
   _device->RemoveBlob(_key);
 }
 
@@ -74,31 +90,31 @@ optional<unique_ref<Blob>> CryNode::LoadBlob() const {
 }
 
 void CryNode::stat(struct ::stat *result) const {
-  if(_parent.get() == nullptr) {
+  if(_parent == none) {
     //We are the root directory.
 	//TODO What should we do?
 	result->st_mode = S_IFDIR;
   } else {
-    _parent->statChild(_key, result);
+    (*_parent)->statChild(_key, result);
   }
 }
 
 void CryNode::chmod(mode_t mode) {
-  if (_parent.get() == nullptr) {
+  if (_parent == none) {
     //We are the root direcory.
 	//TODO What should we do?
 	throw FuseErrnoException(EIO);
   }
-  _parent->chmodChild(_key, mode);
+  (*_parent)->chmodChild(_key, mode);
 }
 
 void CryNode::chown(uid_t uid, gid_t gid) {
-  if (_parent.get() == nullptr) {
+  if (_parent == none) {
 	//We are the root direcory.
 	//TODO What should we do?
 	throw FuseErrnoException(EIO);
   }
-  _parent->chownChild(_key, uid, gid);
+  (*_parent)->chownChild(_key, uid, gid);
 }
 
 }
diff --git a/src/CryNode.h b/src/CryNode.h
index 80d0d787..1b0511bf 100644
--- a/src/CryNode.h
+++ b/src/CryNode.h
@@ -12,7 +12,7 @@ namespace cryfs {
 
 class CryNode: public virtual fspp::Node {
 public:
-  CryNode(CryDevice *device, std::unique_ptr<DirBlob> parent, const blockstore::Key &key);
+  CryNode(CryDevice *device, boost::optional<cpputils::unique_ref<DirBlob>> parent, const blockstore::Key &key);
   void access(int mask) const override;
   void stat(struct ::stat *result) const override;
   void chmod(mode_t mode) override;
@@ -33,7 +33,7 @@ protected:
 
 private:
   CryDevice *_device;
-  std::unique_ptr<DirBlob> _parent;
+  boost::optional<cpputils::unique_ref<DirBlob>> _parent;
   blockstore::Key _key;
 
   DISALLOW_COPY_AND_ASSIGN(CryNode);
diff --git a/src/CryOpenFile.cpp b/src/CryOpenFile.cpp
index 742ced24..33e861ee 100644
--- a/src/CryOpenFile.cpp
+++ b/src/CryOpenFile.cpp
@@ -9,7 +9,7 @@
 
 namespace bf = boost::filesystem;
 
-using std::unique_ptr;
+using cpputils::unique_ref;
 using blobstore::Blob;
 
 //TODO Get rid of this in favor of a exception hierarchy
@@ -18,7 +18,7 @@ using fspp::fuse::FuseErrnoException;
 
 namespace cryfs {
 
-CryOpenFile::CryOpenFile(unique_ptr<FileBlob> fileBlob)
+CryOpenFile::CryOpenFile(unique_ref<FileBlob> fileBlob)
 : _fileBlob(std::move(fileBlob)) {
 }
 
diff --git a/src/CryOpenFile.h b/src/CryOpenFile.h
index 8efcaf6b..c3f5eaf9 100644
--- a/src/CryOpenFile.h
+++ b/src/CryOpenFile.h
@@ -3,7 +3,8 @@
 #define CRYFS_LIB_CRYOPENFILE_H_
 
 #include "messmer/fspp/fs_interface/OpenFile.h"
-#include "messmer/cpp-utils/macros.h"
+#include <messmer/cpp-utils/macros.h>
+#include <messmer/cpp-utils/unique_ref.h>
 
 namespace cryfs {
 class CryDevice;
@@ -11,7 +12,7 @@ class FileBlob;
 
 class CryOpenFile: public fspp::OpenFile {
 public:
-  explicit CryOpenFile(std::unique_ptr<FileBlob> fileBlob);
+  explicit CryOpenFile(cpputils::unique_ref<FileBlob> fileBlob);
   virtual ~CryOpenFile();
 
   void stat(struct ::stat *result) const override;
@@ -23,7 +24,7 @@ public:
   void fdatasync() override;
 
 private:
-  std::unique_ptr<FileBlob> _fileBlob;
+  cpputils::unique_ref<FileBlob> _fileBlob;
 
   DISALLOW_COPY_AND_ASSIGN(CryOpenFile);
 };
diff --git a/src/CrySymlink.cpp b/src/CrySymlink.cpp
index 076db199..82d59e25 100644
--- a/src/CrySymlink.cpp
+++ b/src/CrySymlink.cpp
@@ -18,10 +18,11 @@ using std::vector;
 
 using blockstore::Key;
 using boost::none;
+using cpputils::unique_ref;
 
 namespace cryfs {
 
-CrySymlink::CrySymlink(CryDevice *device, unique_ptr<DirBlob> parent, const Key &key)
+CrySymlink::CrySymlink(CryDevice *device, unique_ref<DirBlob> parent, const Key &key)
 : CryNode(device, std::move(parent), key) {
 }
 
diff --git a/src/CrySymlink.h b/src/CrySymlink.h
index 995ee873..e0190213 100644
--- a/src/CrySymlink.h
+++ b/src/CrySymlink.h
@@ -11,7 +11,7 @@ namespace cryfs {
 
 class CrySymlink: public fspp::Symlink, CryNode {
 public:
-  CrySymlink(CryDevice *device, std::unique_ptr<DirBlob> parent, const blockstore::Key &key);
+  CrySymlink(CryDevice *device, cpputils::unique_ref<DirBlob> parent, const blockstore::Key &key);
   virtual ~CrySymlink();
 
   boost::filesystem::path target() const override;
diff --git a/src/impl/DirBlob.cpp b/src/impl/DirBlob.cpp
index c5d67fd5..2564da5e 100644
--- a/src/impl/DirBlob.cpp
+++ b/src/impl/DirBlob.cpp
@@ -22,6 +22,7 @@ using blobstore::Blob;
 using blockstore::Key;
 using cpputils::Data;
 using cpputils::unique_ref;
+using cpputils::make_unique_ref;
 using boost::none;
 
 namespace cryfs {
@@ -42,11 +43,11 @@ void DirBlob::flush() {
   _blob->flush();
 }
 
-unique_ptr<DirBlob> DirBlob::InitializeEmptyDir(unique_ref<Blob> blob, CryDevice *device) {
+unique_ref<DirBlob> DirBlob::InitializeEmptyDir(unique_ref<Blob> blob, CryDevice *device) {
   blob->resize(1);
   unsigned char magicNumber = MagicNumbers::DIR;
   blob->write(&magicNumber, 0, 1);
-  return make_unique<DirBlob>(std::move(blob), device);
+  return make_unique_ref<DirBlob>(std::move(blob), device);
 }
 
 unsigned char DirBlob::magicNumber() const {
diff --git a/src/impl/DirBlob.h b/src/impl/DirBlob.h
index 143abd8f..39303354 100644
--- a/src/impl/DirBlob.h
+++ b/src/impl/DirBlob.h
@@ -40,7 +40,7 @@ public:
     gid_t gid;
   };
 
-  static std::unique_ptr<DirBlob> InitializeEmptyDir(cpputils::unique_ref<blobstore::Blob> blob, CryDevice *device);
+  static cpputils::unique_ref<DirBlob> InitializeEmptyDir(cpputils::unique_ref<blobstore::Blob> blob, CryDevice *device);
 
   DirBlob(cpputils::unique_ref<blobstore::Blob> blob, CryDevice *device);
   virtual ~DirBlob();
diff --git a/src/impl/FileBlob.cpp b/src/impl/FileBlob.cpp
index fe66843b..8d8966ea 100644
--- a/src/impl/FileBlob.cpp
+++ b/src/impl/FileBlob.cpp
@@ -8,6 +8,7 @@ using std::unique_ptr;
 using std::make_unique;
 using blobstore::Blob;
 using cpputils::unique_ref;
+using cpputils::make_unique_ref;
 
 namespace cryfs {
 
@@ -18,12 +19,12 @@ FileBlob::FileBlob(unique_ref<Blob> blob)
 FileBlob::~FileBlob() {
 }
 
-unique_ptr<FileBlob> FileBlob::InitializeEmptyFile(unique_ref<Blob> blob) {
+unique_ref<FileBlob> FileBlob::InitializeEmptyFile(unique_ref<Blob> blob) {
   assert(blob.get() != nullptr);
   blob->resize(1);
   unsigned char magicNumber = MagicNumbers::FILE;
   blob->write(&magicNumber, 0, 1);
-  return make_unique<FileBlob>(std::move(blob));
+  return make_unique_ref<FileBlob>(std::move(blob));
 }
 
 unsigned char FileBlob::magicNumber() const {
diff --git a/src/impl/FileBlob.h b/src/impl/FileBlob.h
index 8e30b07a..57f50234 100644
--- a/src/impl/FileBlob.h
+++ b/src/impl/FileBlob.h
@@ -10,7 +10,7 @@ namespace cryfs {
 
 class FileBlob {
 public:
-  static std::unique_ptr<FileBlob> InitializeEmptyFile(cpputils::unique_ref<blobstore::Blob> blob);
+  static cpputils::unique_ref<FileBlob> InitializeEmptyFile(cpputils::unique_ref<blobstore::Blob> blob);
 
   FileBlob(cpputils::unique_ref<blobstore::Blob> blob);
   virtual ~FileBlob();
diff --git a/src/impl/SymlinkBlob.cpp b/src/impl/SymlinkBlob.cpp
index aca639b0..7d90eaab 100644
--- a/src/impl/SymlinkBlob.cpp
+++ b/src/impl/SymlinkBlob.cpp
@@ -9,6 +9,7 @@ using std::make_unique;
 using std::string;
 using blobstore::Blob;
 using cpputils::unique_ref;
+using cpputils::make_unique_ref;
 
 namespace bf = boost::filesystem;
 
@@ -24,14 +25,14 @@ SymlinkBlob::SymlinkBlob(const bf::path &target) :_target(target) {
 SymlinkBlob::~SymlinkBlob() {
 }
 
-unique_ptr<SymlinkBlob> SymlinkBlob::InitializeSymlink(unique_ref<Blob> blob, const bf::path &target) {
+unique_ref<SymlinkBlob> SymlinkBlob::InitializeSymlink(unique_ref<Blob> blob, const bf::path &target) {
   assert(blob.get() != nullptr);
   string targetStr = target.native();
   blob->resize(1 + targetStr.size());
   unsigned char magicNumber = MagicNumbers::SYMLINK;
   blob->write(&magicNumber, 0, 1);
   blob->write(targetStr.c_str(), 1, targetStr.size());
-  return make_unique<SymlinkBlob>(target);
+  return make_unique_ref<SymlinkBlob>(target);
 }
 
 void SymlinkBlob::_checkMagicNumber(const Blob &blob) {
diff --git a/src/impl/SymlinkBlob.h b/src/impl/SymlinkBlob.h
index ac88e6a2..a12b3dac 100644
--- a/src/impl/SymlinkBlob.h
+++ b/src/impl/SymlinkBlob.h
@@ -11,7 +11,7 @@ namespace cryfs {
 
 class SymlinkBlob {
 public:
-  static std::unique_ptr<SymlinkBlob> InitializeSymlink(cpputils::unique_ref<blobstore::Blob> blob, const boost::filesystem::path &target);
+  static cpputils::unique_ref<SymlinkBlob> InitializeSymlink(cpputils::unique_ref<blobstore::Blob> blob, const boost::filesystem::path &target);
 
   SymlinkBlob(cpputils::unique_ref<blobstore::Blob> blob);
   SymlinkBlob(const boost::filesystem::path &target);