diff --git a/CMakeLists.txt b/CMakeLists.txt
index db01352..5e271f9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -182,7 +182,7 @@ if (PHMAP_BUILD_EXAMPLES)
         add_executable(ex_lazy_emplace_l examples/lazy_emplace_l.cc phmap.natvis)
     endif()
     add_executable(ex_serialize examples/serialize.cc phmap.natvis)
-    target_include_directories(ex_serialize PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/../cereal/include>)
+    #target_include_directories(ex_serialize PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/../cereal/include>)
     add_executable(ex_hash_std examples/hash_std.cc phmap.natvis)
     add_executable(ex_hash_value examples/hash_value.cc phmap.natvis)
     add_executable(ex_hash examples/hash.cc phmap.natvis)
diff --git a/parallel_hashmap/phmap_base.h b/parallel_hashmap/phmap_base.h
index ffd7cd8..1541e35 100644
--- a/parallel_hashmap/phmap_base.h
+++ b/parallel_hashmap/phmap_base.h
@@ -4869,12 +4869,12 @@ public:
     
     struct AbslMutex : protected absl::Mutex
     {
-        void lock()            { this->Lock(); }
-        void unlock()          { this->Unlock(); }
-        void try_lock()        { this->TryLock(); }
-        void lock_shared()     { this->ReaderLock(); }
-        void unlock_shared()   { this->ReaderUnlock(); }
-        void try_lock_shared() { this->ReaderTryLock(); }
+        void lock()            ABSL_EXCLUSIVE_LOCK_FUNCTION()        { this->Lock(); }
+        void unlock()          ABSL_UNLOCK_FUNCTION()                { this->Unlock(); }
+        void try_lock()        ABSL_EXCLUSIVE_TRYLOCK_FUNCTION(true) { this->TryLock(); }
+        void lock_shared()     ABSL_SHARED_LOCK_FUNCTION()           { this->ReaderLock(); }
+        void unlock_shared()   ABSL_UNLOCK_FUNCTION()                { this->ReaderUnlock(); }
+        void try_lock_shared() ABSL_SHARED_TRYLOCK_FUNCTION(true)    { this->ReaderTryLock(); }
     };
     
     template <>
@@ -4898,7 +4898,6 @@ public:
 // --------------------------------------------------------------------------
 #ifdef BOOST_THREAD_SHARED_MUTEX_HPP
 
-#if 1
     // ---------------------------------------------------------------------------
     template <>
     class  LockableImpl<boost::shared_mutex> : public boost::shared_mutex
@@ -4913,21 +4912,6 @@ public:
         using UniqueLocks     = typename Base::WriteLocks;
         using UpgradeToUnique = typename Base::DoNothing;  // we already have unique ownership
     };
-#else
-    // ---------------------------------------------------------------------------
-    template <>
-    class  LockableImpl<boost::upgrade_mutex> : public boost::upgrade_mutex
-    {
-    public:
-        using mutex_type      = boost::upgrade_mutex;
-        using SharedLock      = boost::shared_lock<mutex_type>;
-        using UpgradeLock     = boost::upgrade_lock<mutex_type>;
-        using UniqueLock      = boost::unique_lock<mutex_type>;
-        using SharedLocks     = typename Base::ReadLocks;
-        using UniqueLocks     = typename Base::WriteLocks;
-        using UpgradeToUnique = boost::upgrade_to_unique_lock<mutex_type>;
-    };
-#endif
 
 #endif // BOOST_THREAD_SHARED_MUTEX_HPP