diff --git a/db/compaction_picker.cc b/db/compaction_picker.cc
index 284942117..9582b6a29 100644
--- a/db/compaction_picker.cc
+++ b/db/compaction_picker.cc
@@ -8,6 +8,8 @@
 // found in the LICENSE file. See the AUTHORS file for names of contributors.
 
 #include "db/compaction_picker.h"
+
+#include <limits>
 #include "util/statistics.h"
 
 namespace rocksdb {
diff --git a/db/db_bench.cc b/db/db_bench.cc
index e41a31cf3..18258fbb6 100644
--- a/db/db_bench.cc
+++ b/db/db_bench.cc
@@ -21,6 +21,8 @@
 #include "rocksdb/env.h"
 #include "rocksdb/memtablerep.h"
 #include "rocksdb/write_batch.h"
+#include "rocksdb/slice.h"
+#include "rocksdb/slice_transform.h"
 #include "rocksdb/statistics.h"
 #include "port/port.h"
 #include "util/bit_set.h"
diff --git a/db/db_test.cc b/db/db_test.cc
index 4fa5452c2..df1d0a5c2 100644
--- a/db/db_test.cc
+++ b/db/db_test.cc
@@ -21,6 +21,8 @@
 #include "rocksdb/cache.h"
 #include "rocksdb/compaction_filter.h"
 #include "rocksdb/env.h"
+#include "rocksdb/slice.h"
+#include "rocksdb/slice_transform.h"
 #include "rocksdb/table.h"
 #include "util/hash.h"
 #include "util/logging.h"
diff --git a/db/prefix_filter_iterator.h b/db/prefix_filter_iterator.h
index f4488379c..e868c7a54 100644
--- a/db/prefix_filter_iterator.h
+++ b/db/prefix_filter_iterator.h
@@ -12,6 +12,8 @@
 
 #pragma once
 #include "rocksdb/iterator.h"
+#include "rocksdb/slice.h"
+#include "rocksdb/slice_transform.h"
 
 namespace rocksdb {
 
diff --git a/db/skiplist.h b/db/skiplist.h
index 06a35d911..2c9c4a6de 100644
--- a/db/skiplist.h
+++ b/db/skiplist.h
@@ -35,6 +35,7 @@
 #include <stdlib.h>
 #include "port/port.h"
 #include "util/random.h"
+#include "rocksdb/arena.h"
 
 namespace rocksdb {
 
diff --git a/db/tailing_iter.cc b/db/tailing_iter.cc
index f448ac15d..5644b1211 100644
--- a/db/tailing_iter.cc
+++ b/db/tailing_iter.cc
@@ -8,6 +8,8 @@
 #include <string>
 #include <utility>
 #include "db/db_impl.h"
+#include "rocksdb/slice.h"
+#include "rocksdb/slice_transform.h"
 
 namespace rocksdb {
 
diff --git a/db/version_set.cc b/db/version_set.cc
index b8f87dc11..61fca24f2 100644
--- a/db/version_set.cc
+++ b/db/version_set.cc
@@ -1925,8 +1925,11 @@ Status VersionSet::ReduceNumberOfLevels(const std::string& dbname,
   }
 
   std::vector<FileMetaData*>* old_files_list = current_version->files_;
+  // we need to allocate an array with the old number of levels size to
+  // avoid SIGSEGV in WriteSnapshot()
+  // however, all levels bigger or equal to new_levels will be empty
   std::vector<FileMetaData*>* new_files_list =
-      new std::vector<FileMetaData*>[new_levels];
+      new std::vector<FileMetaData*>[current_levels];
   for (int i = 0; i < new_levels - 1; i++) {
     new_files_list[i] = old_files_list[i];
   }
diff --git a/include/rocksdb/memtablerep.h b/include/rocksdb/memtablerep.h
index 2fca8d161..9e24942ac 100644
--- a/include/rocksdb/memtablerep.h
+++ b/include/rocksdb/memtablerep.h
@@ -37,12 +37,13 @@
 #define STORAGE_ROCKSDB_DB_MEMTABLEREP_H_
 
 #include <memory>
-#include "rocksdb/arena.h"
-#include "rocksdb/slice.h"
-#include "rocksdb/slice_transform.h"
 
 namespace rocksdb {
 
+class Arena;
+class Slice;
+class SliceTransform;
+
 class MemTableRep {
  public:
   // KeyComparator provides a means to compare keys, which are internal keys
diff --git a/include/rocksdb/options.h b/include/rocksdb/options.h
index 76fdcc81e..00acafb0a 100644
--- a/include/rocksdb/options.h
+++ b/include/rocksdb/options.h
@@ -15,11 +15,6 @@
 #include <vector>
 #include <stdint.h>
 
-#include "rocksdb/memtablerep.h"
-#include "rocksdb/slice.h"
-#include "rocksdb/slice_transform.h"
-#include "rocksdb/statistics.h"
-#include "rocksdb/table_properties.h"
 #include "rocksdb/universal_compaction.h"
 
 namespace rocksdb {
@@ -34,6 +29,11 @@ class Logger;
 class MergeOperator;
 class Snapshot;
 class TableFactory;
+class MemTableRepFactory;
+class TablePropertiesCollector;
+class Slice;
+class SliceTransform;
+class Statistics;
 
 using std::shared_ptr;
 
diff --git a/include/rocksdb/universal_compaction.h b/include/rocksdb/universal_compaction.h
index ec862b95f..eaf47e5c7 100644
--- a/include/rocksdb/universal_compaction.h
+++ b/include/rocksdb/universal_compaction.h
@@ -6,14 +6,8 @@
 #ifndef STORAGE_ROCKSDB_UNIVERSAL_COMPACTION_OPTIONS_H
 #define STORAGE_ROCKSDB_UNIVERSAL_COMPACTION_OPTIONS_H
 
-#include <stddef.h>
-#include <string>
-#include <memory>
-#include <vector>
 #include <stdint.h>
 #include <climits>
-#include "rocksdb/slice.h"
-#include "rocksdb/statistics.h"
 
 namespace rocksdb {
 
diff --git a/tools/db_stress.cc b/tools/db_stress.cc
index 8321c7eaf..bad2cf0d6 100644
--- a/tools/db_stress.cc
+++ b/tools/db_stress.cc
@@ -31,6 +31,8 @@
 #include "utilities/utility_db.h"
 #include "rocksdb/env.h"
 #include "rocksdb/write_batch.h"
+#include "rocksdb/slice.h"
+#include "rocksdb/slice_transform.h"
 #include "rocksdb/statistics.h"
 #include "port/port.h"
 #include "util/coding.h"
diff --git a/util/coding.cc b/util/coding.cc
index ce67fa486..6cf67efad 100644
--- a/util/coding.cc
+++ b/util/coding.cc
@@ -9,6 +9,10 @@
 
 #include "util/coding.h"
 
+#include "rocksdb/slice.h"
+#include "rocksdb/slice_transform.h"
+
+
 #include <algorithm>
 
 namespace rocksdb {
diff --git a/util/coding.h b/util/coding.h
index 4477dc799..c6a6b203d 100644
--- a/util/coding.h
+++ b/util/coding.h
@@ -16,6 +16,8 @@
 #include <stdint.h>
 #include <string.h>
 #include <string>
+
+#include "rocksdb/write_batch.h"
 #include "port/port.h"
 
 namespace rocksdb {
diff --git a/util/options.cc b/util/options.cc
index 96f86f5c6..e4a14c1da 100644
--- a/util/options.cc
+++ b/util/options.cc
@@ -17,6 +17,10 @@
 #include "rocksdb/env.h"
 #include "rocksdb/filter_policy.h"
 #include "rocksdb/merge_operator.h"
+#include "rocksdb/memtablerep.h"
+#include "rocksdb/slice.h"
+#include "rocksdb/slice_transform.h"
+#include "rocksdb/table_properties.h"
 #include "table/block_based_table_factory.h"
 
 namespace rocksdb {
diff --git a/utilities/backupable/backupable_db.cc b/utilities/backupable/backupable_db.cc
index 26bdd254b..8e5ef5220 100644
--- a/utilities/backupable/backupable_db.cc
+++ b/utilities/backupable/backupable_db.cc
@@ -21,6 +21,7 @@
 #include <string>
 #include <limits>
 #include <atomic>
+#include <unordered_map>
 
 namespace rocksdb {