diff --git a/toonz/sources/common/tcore/tidentifiable.cpp b/toonz/sources/common/tcore/tidentifiable.cpp
deleted file mode 100644
index a58c29f..0000000
--- a/toonz/sources/common/tcore/tidentifiable.cpp
+++ /dev/null
@@ -1,87 +0,0 @@
-
-
-#include "tidentifiable.h"
-#include <set>
-
-namespace {
-
-class IdentifierTable {  // singleton
-
-  unsigned long m_lastId;
-  std::map<unsigned long, TIdentifiable *> m_table;
-  std::set<TIdentifiable *> m_objects;
-
-  IdentifierTable() : m_lastId(0) {}
-
-public:
-  static IdentifierTable *instance() {
-    // NON DEVE MORIRE
-    // static IdentifierTable _instance;
-    // return &_instance;
-    static IdentifierTable *_instance = 0;
-    if (!_instance) _instance         = new IdentifierTable;
-    return _instance;
-  }
-
-  unsigned long getNextId() { return ++m_lastId; }
-
-  void insert(TIdentifiable *o) {
-    unsigned long id = o->getIdentifier();
-    std::map<unsigned long, TIdentifiable *>::iterator it = m_table.find(id);
-    if (it != m_table.end()) {
-      if (it->second == o) return;
-      m_objects.erase(it->second);
-      it->second = o;
-    } else {
-      m_table[id] = o;
-    }
-    m_objects.insert(o);
-  }
-
-  void erase(TIdentifiable *o) {
-    unsigned long id = o->getIdentifier();
-    m_table.erase(id);
-    m_objects.erase(o);
-  }
-
-  TIdentifiable *fetch(unsigned long id) {
-    std::map<unsigned long, TIdentifiable *>::iterator it = m_table.find(id);
-    return it == m_table.end() ? 0 : it->second;
-  }
-};
-
-}  // namespace
-
-TIdentifiable::TIdentifiable() : m_id(0) {}
-
-TIdentifiable::~TIdentifiable() {
-  if (m_id != 0) IdentifierTable::instance()->erase(this);
-}
-
-TIdentifiable::TIdentifiable(const TIdentifiable &src) : m_id(src.m_id) {}
-
-const TIdentifiable &TIdentifiable::operator=(const TIdentifiable &src) {
-  if (src.m_id != m_id && m_id != 0) IdentifierTable::instance()->erase(this);
-  m_id = src.m_id;
-  return *this;
-}
-
-void TIdentifiable::setIdentifier(unsigned long id) {
-  bool wasStored = m_id > 0 && IdentifierTable::instance()->fetch(m_id) == this;
-  if (m_id != id && m_id != 0) IdentifierTable::instance()->erase(this);
-  m_id = id;
-  if (wasStored) IdentifierTable::instance()->insert(this);
-}
-
-void TIdentifiable::setNewIdentifier() {
-  setIdentifier(IdentifierTable::instance()->getNextId());
-}
-
-void TIdentifiable::storeByIdentifier() {
-  assert(getIdentifier() >= 1);
-  IdentifierTable::instance()->insert(this);
-}
-
-TIdentifiable *TIdentifiable::fetchByIdentifier(unsigned long id) {
-  return IdentifierTable::instance()->fetch(id);
-}
diff --git a/toonz/sources/include/tidentifiable.h b/toonz/sources/include/tidentifiable.h
deleted file mode 100644
index 2679d13..0000000
--- a/toonz/sources/include/tidentifiable.h
+++ /dev/null
@@ -1,37 +0,0 @@
-#pragma once
-
-#ifndef TIDENTIFIABLE_INCLUDED
-#define TIDENTIFIABLE_INCLUDED
-
-#include "tutil.h"
-
-#undef DVAPI
-#undef DVVAR
-#ifdef TNZCORE_EXPORTS
-#define DVAPI DV_EXPORT_API
-#define DVVAR DV_EXPORT_VAR
-#else
-#define DVAPI DV_IMPORT_API
-#define DVVAR DV_IMPORT_VAR
-#endif
-
-//=========================================================
-
-class DVAPI TIdentifiable {
-  unsigned long m_id;
-
-public:
-  TIdentifiable();
-  virtual ~TIdentifiable();
-  TIdentifiable(const TIdentifiable &);
-  const TIdentifiable &operator=(const TIdentifiable &);
-
-  unsigned long getIdentifier() const { return m_id; }
-  void setIdentifier(unsigned long id);
-  void setNewIdentifier();
-
-  void storeByIdentifier();
-  static TIdentifiable *fetchByIdentifier(unsigned long id);
-};
-
-#endif
diff --git a/toonz/sources/tnzcore/CMakeLists.txt b/toonz/sources/tnzcore/CMakeLists.txt
index 6873c47..d637cd2 100644
--- a/toonz/sources/tnzcore/CMakeLists.txt
+++ b/toonz/sources/tnzcore/CMakeLists.txt
@@ -34,7 +34,6 @@ set(HEADERS ${MOC_HEADERS}
     ../include/tdebugmessage.h
     ../include/texception.h
     ../include/texpression.h
-    ../include/tidentifiable.h
     ../include/tmathutil.h
     ../include/tnztypes.h
     ../include/tproperty.h
@@ -129,7 +128,6 @@ set(SOURCES
     ../common/tcore/tdebugmessage.cpp
     ../common/tcore/texception.cpp
     ../common/tcore/threadmessage.cpp
-    ../common/tcore/tidentifiable.cpp
     ../common/tcore/tmathutil.cpp
     ../common/tproperty.cpp
     ../common/tcore/trandom.cpp