diff --git a/db/db_test.cc b/db/db_test.cc
index 1e39454df..5b21b2f1b 100644
--- a/db/db_test.cc
+++ b/db/db_test.cc
@@ -240,6 +240,8 @@ class SpecialEnv : public EnvWrapper {
 class DBTest {
  private:
   const FilterPolicy* filter_policy_;
+  static std::unique_ptr<const SliceTransform> prefix_1_transform;
+  static std::unique_ptr<const SliceTransform> noop_transform;
 
  protected:
   // Sequence of option configurations to try
@@ -356,13 +358,13 @@ class DBTest {
         break;
       case kPlainTableFirstBytePrefix:
         options.table_factory.reset(new PlainTableFactory());
-        options.prefix_extractor = NewFixedPrefixTransform(1);
+        options.prefix_extractor = prefix_1_transform.get();
         options.allow_mmap_reads = true;
         options.max_sequential_skip_in_iterations = 999999;
         break;
       case kPlainTableAllBytesPrefix:
         options.table_factory.reset(new PlainTableFactory());
-        options.prefix_extractor = NewNoopTransform();
+        options.prefix_extractor = noop_transform.get();
         options.allow_mmap_reads = true;
         options.max_sequential_skip_in_iterations = 999999;
         break;
@@ -694,6 +696,10 @@ class DBTest {
     delete iter;
   }
 };
+std::unique_ptr<const SliceTransform> DBTest::prefix_1_transform(
+    NewFixedPrefixTransform(1));
+std::unique_ptr<const SliceTransform> DBTest::noop_transform(
+    NewNoopTransform());
 
 static std::string Key(int i) {
   char buf[100];
@@ -4694,20 +4700,22 @@ TEST(DBTest, PrefixScan) {
   snprintf(buf, sizeof(buf), "03______:");
   prefix = Slice(buf, 8);
   key = Slice(buf, 9);
-  auto prefix_extractor = NewFixedPrefixTransform(8);
   // db configs
   env_->count_random_reads_ = true;
   Options options = CurrentOptions();
   options.env = env_;
   options.no_block_cache = true;
-  options.filter_policy =  NewBloomFilterPolicy(10);
-  options.prefix_extractor = prefix_extractor;
+  options.filter_policy = NewBloomFilterPolicy(10);
+  options.prefix_extractor = NewFixedPrefixTransform(8);
   options.whole_key_filtering = false;
   options.disable_auto_compactions = true;
   options.max_background_compactions = 2;
   options.create_if_missing = true;
   options.disable_seek_compaction = true;
-  options.memtable_factory.reset(NewHashSkipListRepFactory(prefix_extractor));
+  // Tricky: options.prefix_extractor will be released by
+  // NewHashSkipListRepFactory after use.
+  options.memtable_factory.reset(
+      NewHashSkipListRepFactory(options.prefix_extractor));
 
   // prefix specified, with blooms: 2 RAND I/Os
   // SeekToFirst
diff --git a/db/plain_table_db_test.cc b/db/plain_table_db_test.cc
index 17f871e4c..1ead9729a 100644
--- a/db/plain_table_db_test.cc
+++ b/db/plain_table_db_test.cc
@@ -35,16 +35,17 @@ using std::unique_ptr;
 namespace rocksdb {
 
 class PlainTableDBTest {
-protected:
-public:
+ protected:
+ private:
   std::string dbname_;
   Env* env_;
   DB* db_;
 
   Options last_options_;
+  static std::unique_ptr<const SliceTransform> prefix_transform;
 
-  PlainTableDBTest() :
-      env_(Env::Default()) {
+ public:
+  PlainTableDBTest() : env_(Env::Default()) {
     dbname_ = test::TmpDir() + "/plain_table_db_test";
     ASSERT_OK(DestroyDB(dbname_, Options()));
     db_ = nullptr;
@@ -60,7 +61,7 @@ public:
   Options CurrentOptions() {
     Options options;
     options.table_factory.reset(new PlainTableFactory(16, 2, 0.8));
-    options.prefix_extractor = NewFixedPrefixTransform(8);
+    options.prefix_extractor = prefix_transform.get();
     options.allow_mmap_reads = true;
     return options;
   }
@@ -167,8 +168,11 @@ public:
   }
 };
 
+std::unique_ptr<const SliceTransform> PlainTableDBTest::prefix_transform(
+    NewFixedPrefixTransform(8));
+
 TEST(PlainTableDBTest, Empty) {
-  ASSERT_TRUE(db_ != nullptr);
+  ASSERT_TRUE(dbfull() != nullptr);
   ASSERT_EQ("NOT_FOUND", Get("0000000000000foo"));
 }
 
diff --git a/table/table_test.cc b/table/table_test.cc
index bff8ee529..a36e726a1 100644
--- a/table/table_test.cc
+++ b/table/table_test.cc
@@ -647,7 +647,7 @@ class Harness {
       case PLAIN_TABLE_FULL_STR_PREFIX:
         support_prev_ = false;
         only_support_prefix_seek_ = true;
-        options_.prefix_extractor = NewNoopTransform();
+        options_.prefix_extractor = noop_transform.get();
         options_.allow_mmap_reads = true;
         options_.table_factory.reset(new PlainTableFactory());
         constructor_ = new TableConstructor(options_.comparator, true);
@@ -849,8 +849,12 @@ class Harness {
   bool support_prev_;
   bool only_support_prefix_seek_;
   shared_ptr<Comparator> internal_comparator_;
+  static std::unique_ptr<const SliceTransform> noop_transform;
 };
 
+std::unique_ptr<const SliceTransform> Harness::noop_transform(
+    NewNoopTransform());
+
 static bool Between(uint64_t val, uint64_t low, uint64_t high) {
   bool result = (val >= low) && (val <= high);
   if (!result) {