diff --git a/arangod/Indexes/SkiplistIndex.cpp b/arangod/Indexes/SkiplistIndex.cpp
index 208a2277d9..17d2f6e31a 100644
--- a/arangod/Indexes/SkiplistIndex.cpp
+++ b/arangod/Indexes/SkiplistIndex.cpp
@@ -876,7 +876,7 @@ int SkiplistIndex::remove(arangodb::Transaction*, TRI_doc_mptr_t const* doc,
 }
 
 int SkiplistIndex::unload() {
-  _skiplistIndex->truncate();
+  _skiplistIndex->truncate(true);
   return TRI_ERROR_NO_ERROR;
 }
 
diff --git a/arangod/StorageEngine/MMFilesCollection.cpp b/arangod/StorageEngine/MMFilesCollection.cpp
index 52a3d4d72d..efb1436c38 100644
--- a/arangod/StorageEngine/MMFilesCollection.cpp
+++ b/arangod/StorageEngine/MMFilesCollection.cpp
@@ -56,16 +56,6 @@ MMFilesCollection::MMFilesCollection(LogicalCollection* collection)
 
 MMFilesCollection::~MMFilesCollection() {
   close();
-
-  for (auto& it : _datafiles) {
-    delete it;
-  }
-  for (auto& it : _journals) {
-    delete it;
-  }
-  for (auto& it : _compactors) {
-    delete it;
-  }
 }
   
 TRI_voc_rid_t MMFilesCollection::revision() const { 
@@ -83,14 +73,23 @@ int64_t MMFilesCollection::initialCount() const {
 int MMFilesCollection::close() {
   // close compactor files
   closeDatafiles(_compactors);
+  for (auto& it : _compactors) {
+    delete it;
+  }
   _compactors.clear();
 
   // close journal files
   closeDatafiles(_journals);
+  for (auto& it : _journals) {
+    delete it;
+  }
   _journals.clear();
 
   // close datafiles
   closeDatafiles(_datafiles);
+  for (auto& it : _datafiles) {
+    delete it;
+  }
   _datafiles.clear();
 
   return TRI_ERROR_NO_ERROR;
diff --git a/arangod/StorageEngine/MMFilesEngine.cpp b/arangod/StorageEngine/MMFilesEngine.cpp
index dfa79636df..10b1ea1c05 100644
--- a/arangod/StorageEngine/MMFilesEngine.cpp
+++ b/arangod/StorageEngine/MMFilesEngine.cpp
@@ -1856,10 +1856,9 @@ int MMFilesEngine::openCollection(TRI_vocbase_t* vocbase, LogicalCollection* col
         filename = newName;
       }
 
-      TRI_datafile_t* datafile =
-          TRI_OpenDatafile(filename, ignoreErrors);
+      std::unique_ptr<TRI_datafile_t> df(TRI_OpenDatafile(filename, ignoreErrors));
 
-      if (datafile == nullptr) {
+      if (df == nullptr) {
         LOG_TOPIC(ERR, Logger::DATAFILES) << "cannot open datafile '"
                                           << filename
                                           << "': " << TRI_last_error();
@@ -1868,7 +1867,8 @@ int MMFilesEngine::openCollection(TRI_vocbase_t* vocbase, LogicalCollection* col
         break;
       }
 
-      all.emplace_back(datafile);
+      all.emplace_back(df.get());
+      TRI_datafile_t* datafile = df.release();
 
       // check the document header
       char const* ptr = datafile->_data;
diff --git a/arangod/VocBase/datafile.cpp b/arangod/VocBase/datafile.cpp
index 410e31dde2..98d57c5d8b 100644
--- a/arangod/VocBase/datafile.cpp
+++ b/arangod/VocBase/datafile.cpp
@@ -1895,7 +1895,7 @@ int TRI_datafile_t::close() {
   } 
   
   if (_state == TRI_DF_STATE_CLOSED) {
-    LOG(WARN) << "closing an already closed datafile '" << getName() << "'";
+    LOG(TRACE) << "closing an already closed datafile '" << getName() << "'";
     return TRI_ERROR_NO_ERROR;
   } 
   
diff --git a/lib/Basics/SkipList.h b/lib/Basics/SkipList.h
index 8a9da897de..4c6c564ba0 100644
--- a/lib/Basics/SkipList.h
+++ b/lib/Basics/SkipList.h
@@ -172,10 +172,10 @@ class SkipList {
   //////////////////////////////////////////////////////////////////////////////
 
   ~SkipList() {
-    truncate();
+    truncate(false);
   }
 
-  void truncate() {
+  void truncate(bool createStartNode) {
     Node* p;
     Node* next;
 
@@ -193,9 +193,12 @@ class SkipList {
     
     _memoryUsed = sizeof(SkipList);
     _nrUsed = 0;
-    _start = allocNode(TRI_SKIPLIST_MAX_HEIGHT);
-    // Note that this can throw
-    _end = _start;
+
+    if (createStartNode) {
+      _start = allocNode(TRI_SKIPLIST_MAX_HEIGHT);
+      // Note that this can throw
+      _end = _start;
+    }
   }
 
   //////////////////////////////////////////////////////////////////////////////