diff --git a/src/app/context_flags.cpp b/src/app/context_flags.cpp
index ea81294e5..cb6d81ea2 100644
--- a/src/app/context_flags.cpp
+++ b/src/app/context_flags.cpp
@@ -37,7 +37,7 @@ void ContextFlags::update(Context* context)
   if (document) {
     m_flags |= HasActiveDocument;
 
-    if (document->lock(Doc::ReadLock, 0)) {
+    if (document->readLock(0)) {
       m_flags |= ActiveDocumentIsReadable;
 
       if (document->isMaskVisible())
diff --git a/src/app/doc.cpp b/src/app/doc.cpp
index 6d4958b19..db4882f3f 100644
--- a/src/app/doc.cpp
+++ b/src/app/doc.cpp
@@ -95,6 +95,46 @@ void Doc::setContext(Context* ctx)
   onContextChanged();
 }
 
+bool Doc::canWriteLockFromRead() const
+{
+  return m_rwLock.canWriteLockFromRead();
+}
+
+bool Doc::readLock(int timeout)
+{
+  return m_rwLock.lock(base::RWLock::ReadLock, timeout);
+}
+
+bool Doc::writeLock(int timeout)
+{
+  return m_rwLock.lock(base::RWLock::WriteLock, timeout);
+}
+
+bool Doc::upgradeToWrite(int timeout)
+{
+  return m_rwLock.upgradeToWrite(timeout);
+}
+
+void Doc::downgradeToRead()
+{
+  m_rwLock.downgradeToRead();
+}
+
+void Doc::unlock()
+{
+  m_rwLock.unlock();
+}
+
+bool Doc::weakLock(base::RWLock::WeakLock* weak_lock_flag)
+{
+  return m_rwLock.weakLock(weak_lock_flag);
+}
+
+void Doc::weakUnlock()
+{
+  m_rwLock.weakUnlock();
+}
+
 void Doc::setTransaction(Transaction* transaction)
 {
   if (transaction) {
diff --git a/src/app/doc.h b/src/app/doc.h
index eb5590ab0..e2cea2bfc 100644
--- a/src/app/doc.h
+++ b/src/app/doc.h
@@ -57,7 +57,6 @@ namespace app {
   // An application document. It is the class used to contain one file
   // opened and being edited by the user (a sprite).
   class Doc : public doc::Document,
-              public base::RWLock,
               public obs::observable<DocObserver> {
     enum Flags {
       kAssociatedToFile = 1, // This sprite is associated to a file in the file-system
@@ -72,6 +71,17 @@ namespace app {
     Context* context() const { return m_ctx; }
     void setContext(Context* ctx);
 
+    // Lock/unlock API (RWLock wrapper)
+    bool canWriteLockFromRead() const;
+    bool readLock(int timeout);
+    bool writeLock(int timeout);
+    bool upgradeToWrite(int timeout);
+    void downgradeToRead();
+    void unlock();
+
+    bool weakLock(base::RWLock::WeakLock* weak_lock_flag);
+    void weakUnlock();
+
     // Sets active/running transaction.
     void setTransaction(Transaction* transaction);
     Transaction* transaction() { return m_transaction; }
@@ -214,9 +224,15 @@ namespace app {
     void removeFromContext();
     void updateOSColorSpace(bool appWideSignal);
 
+    // The document is in the collection of documents of this context.
     Context* m_ctx;
+
+    // Internal states of the document.
     int m_flags;
 
+    // Read-Write locks.
+    base::RWLock m_rwLock;
+
     // Undo and redo information about the document.
     std::unique_ptr<DocUndo> m_undo;
 
diff --git a/src/app/doc_access.h b/src/app/doc_access.h
index 42cf7cc3c..730e09ef1 100644
--- a/src/app/doc_access.h
+++ b/src/app/doc_access.h
@@ -82,13 +82,13 @@ namespace app {
 
     explicit DocReader(Doc* doc, int timeout)
       : DocAccess(doc) {
-      if (m_doc && !m_doc->lock(Doc::ReadLock, timeout))
+      if (m_doc && !m_doc->readLock(timeout))
         throw CannotReadDocException();
     }
 
     explicit DocReader(const DocReader& copy, int timeout)
       : DocAccess(copy) {
-      if (m_doc && !m_doc->lock(Doc::ReadLock, timeout))
+      if (m_doc && !m_doc->readLock(timeout))
         throw CannotReadDocException();
     }
 
@@ -126,7 +126,7 @@ namespace app {
       , m_from_reader(false)
       , m_locked(false) {
       if (m_doc) {
-        if (!m_doc->lock(Doc::WriteLock, timeout))
+        if (!m_doc->writeLock(timeout))
           throw CannotWriteDocException();
 
         m_locked = true;