diff --git a/db/version_set.h b/db/version_set.h
index c8297f8ec..13a138341 100644
--- a/db/version_set.h
+++ b/db/version_set.h
@@ -219,7 +219,7 @@ class Version {
   friend class UniversalCompactionPicker;
 
   class LevelFileNumIterator;
-  struct LevelFileIteratorState;
+  class LevelFileIteratorState;
 
   bool PrefixMayMatch(const ReadOptions& options, Iterator* level_iter,
                       const Slice& internal_prefix) const;
diff --git a/table/block_based_table_reader.h b/table/block_based_table_reader.h
index fbe47272e..f68d6423d 100644
--- a/table/block_based_table_reader.h
+++ b/table/block_based_table_reader.h
@@ -111,7 +111,7 @@ class BlockBasedTable : public TableReader {
   Rep* rep_;
   bool compaction_optimized_;
 
-  struct BlockEntryIteratorState;
+  class BlockEntryIteratorState;
   static Iterator* NewDataBlockIterator(Rep* rep, const ReadOptions& ro,
       bool* didIO, const Slice& index_value);
 
diff --git a/utilities/backupable/backupable_db.cc b/utilities/backupable/backupable_db.cc
index ca1fb504a..a11720165 100644
--- a/utilities/backupable/backupable_db.cc
+++ b/utilities/backupable/backupable_db.cc
@@ -1134,9 +1134,9 @@ Status BackupEngineImpl::BackupMeta::StoreToFile(bool sync) {
 // -------- BackupEngineReadOnlyImpl ---------
 class BackupEngineReadOnlyImpl : public BackupEngineReadOnly {
  public:
-  BackupEngineReadOnlyImpl(Env* db_env, const BackupableDBOptions& options) {
-    backup_engine_ = new BackupEngineImpl(db_env, options, true);
-  }
+  BackupEngineReadOnlyImpl(Env* db_env, const BackupableDBOptions& options)
+      : backup_engine_(new BackupEngineImpl(db_env, options, true)) {}
+
   virtual ~BackupEngineReadOnlyImpl() {}
 
   virtual void GetBackupInfo(std::vector<BackupInfo>* backup_info) {
@@ -1158,7 +1158,7 @@ class BackupEngineReadOnlyImpl : public BackupEngineReadOnly {
   }
 
  private:
-  BackupEngineImpl* backup_engine_;
+  std::unique_ptr<BackupEngineImpl> backup_engine_;
 };
 
 BackupEngineReadOnly* BackupEngineReadOnly::NewReadOnlyBackupEngine(