diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 7d407719..2443f9d6 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -502,6 +502,7 @@ set(SRC_CORE
   	${CMAKE_CURRENT_SOURCE_DIR}/utils/guid.cpp    
   	${CMAKE_CURRENT_SOURCE_DIR}/utils/md5.cpp  
   	${CMAKE_CURRENT_SOURCE_DIR}/utils/memory.cpp
+  	${CMAKE_CURRENT_SOURCE_DIR}/utils/mutex.cpp
 )
 
 
diff --git a/src/debugsymboltable.cpp b/src/debugsymboltable.cpp
index 720f8448..4c7106c8 100644
--- a/src/debugsymboltable.cpp
+++ b/src/debugsymboltable.cpp
@@ -215,16 +215,23 @@ void debugSymbolPage_t::print(void)
 //--------------------------------------------------------------
 debugSymbolTable_t::debugSymbolTable_t(void)
 {
-
+	cs = new FCEU::mutex();
 }
 //--------------------------------------------------------------
 debugSymbolTable_t::~debugSymbolTable_t(void)
 {
 	this->clear();
+
+	if (cs)
+	{
+		delete cs;
+	}
 }
 //--------------------------------------------------------------
 void debugSymbolTable_t::clear(void)
 {
+	FCEU::autoScopedLock alock(cs);
+
 	std::map <int, debugSymbolPage_t*>::iterator it;
 
 	for (it=pageMap.begin(); it!=pageMap.end(); it++)
@@ -305,6 +312,7 @@ int debugSymbolTable_t::loadFileNL( int bank )
 	char stmp[512], line[512];
 	debugSymbolPage_t *page = NULL;
 	debugSymbol_t *sym = NULL;
+	FCEU::autoScopedLock alock(cs);
 
 	//printf("Looking to Load Debug Bank: $%X \n", bank );
 
@@ -544,6 +552,7 @@ int debugSymbolTable_t::loadFileNL( int bank )
 //--------------------------------------------------------------
 int debugSymbolTable_t::loadRegisterMap(void)
 {
+	FCEU::autoScopedLock alock(cs);
 	debugSymbolPage_t *page;
 
 	page = new debugSymbolPage_t();
@@ -627,6 +636,7 @@ int debugSymbolTable_t::addSymbolAtBankOffset( int bank, int ofs, debugSymbol_t
 {
 	debugSymbolPage_t *page;
 	std::map <int, debugSymbolPage_t*>::iterator it;
+	FCEU::autoScopedLock alock(cs);
 
 	it = pageMap.find( bank );
 
@@ -649,6 +659,7 @@ int debugSymbolTable_t::deleteSymbolAtBankOffset( int bank, int ofs )
 {
 	debugSymbolPage_t *page;
 	std::map <int, debugSymbolPage_t*>::iterator it;
+	FCEU::autoScopedLock alock(cs);
 
 	it = pageMap.find( bank );
 
@@ -666,6 +677,8 @@ int debugSymbolTable_t::deleteSymbolAtBankOffset( int bank, int ofs )
 //--------------------------------------------------------------
 debugSymbol_t *debugSymbolTable_t::getSymbolAtBankOffset( int bank, int ofs )
 {
+	FCEU::autoScopedLock alock(cs);
+
 	auto it = pageMap.find( bank );
 
 	return it != pageMap.end() ? it->second->getSymbolAtOffset( ofs ) : NULL;
@@ -673,6 +686,8 @@ debugSymbol_t *debugSymbolTable_t::getSymbolAtBankOffset( int bank, int ofs )
 //--------------------------------------------------------------
 debugSymbol_t *debugSymbolTable_t::getSymbol( int bank, const std::string &name )
 {
+	FCEU::autoScopedLock alock(cs);
+
 	auto it = pageMap.find( bank );
 
 	return it != pageMap.end() ? it->second->getSymbol( name ) : NULL;
@@ -680,6 +695,8 @@ debugSymbol_t *debugSymbolTable_t::getSymbol( int bank, const std::string &name
 //--------------------------------------------------------------
 debugSymbol_t *debugSymbolTable_t::getSymbolAtAnyBank( const std::string &name )
 {
+	FCEU::autoScopedLock alock(cs);
+
 	for (auto &page : pageMap)
 	{
 		auto sym = getSymbol( page.first, name );
@@ -697,6 +714,7 @@ void debugSymbolTable_t::save(void)
 {
 	debugSymbolPage_t *page;
 	std::map <int, debugSymbolPage_t*>::iterator it;
+	FCEU::autoScopedLock alock(cs);
 
 	for (it=pageMap.begin(); it!=pageMap.end(); it++)
 	{
@@ -710,6 +728,7 @@ void debugSymbolTable_t::print(void)
 {
 	debugSymbolPage_t *page;
 	std::map <int, debugSymbolPage_t*>::iterator it;
+	FCEU::autoScopedLock alock(cs);
 
 	for (it=pageMap.begin(); it!=pageMap.end(); it++)
 	{
diff --git a/src/debugsymboltable.h b/src/debugsymboltable.h
index cc0518bd..e77d0aca 100644
--- a/src/debugsymboltable.h
+++ b/src/debugsymboltable.h
@@ -4,6 +4,8 @@
 #include <string>
 #include <map>
 
+#include "utils/mutex.h"
+
 struct debugSymbol_t
 {
 	int   ofs;
@@ -103,6 +105,7 @@ class debugSymbolTable_t
 
 	private:
 		std::map <int, debugSymbolPage_t*> pageMap;
+		FCEU::mutex *cs;
 
 		int loadRegisterMap(void);
 
diff --git a/src/utils/mutex.cpp b/src/utils/mutex.cpp
new file mode 100644
index 00000000..0556ea07
--- /dev/null
+++ b/src/utils/mutex.cpp
@@ -0,0 +1,71 @@
+// mutex.cpp
+#include <cstdio>
+
+#include "mutex.h"
+
+namespace FCEU
+{
+
+//-----------------------------------------------------
+// Cross platform mutex 
+// __QT_DRIVER__  multi-threaded application that uses Qt mutex implementation for synchronization
+// __WIN_DRIVER__ is single thread application so sync methods are unimplemented.
+//-----------------------------------------------------
+mutex::mutex(void)
+{
+#ifdef __QT_DRIVER__
+	#if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
+	mtx = new QRecursiveMutex();
+	#else
+	mtx = new QMutex( QMutex::Recursive );
+	#endif
+#endif
+
+}
+
+mutex::~mutex(void)
+{
+#ifdef __QT_DRIVER__
+	if (mtx)
+	{
+		delete mtx;
+		mtx = nullptr;
+	}
+#endif
+}
+
+void mutex::lock(void)
+{
+#ifdef __QT_DRIVER__
+	mtx->lock();
+#endif
+}
+
+void mutex::unlock(void)
+{
+#ifdef __QT_DRIVER__
+	mtx->unlock();
+#endif
+}
+
+//-----------------------------------------------------
+// Scoped AutoLock
+//-----------------------------------------------------
+autoScopedLock::autoScopedLock( mutex *mtx )
+{
+	m = mtx;
+	if (m)
+	{
+		m->lock();
+	}
+}
+
+autoScopedLock::~autoScopedLock(void)
+{
+	if (m)
+	{
+		m->unlock();
+	}
+}
+
+};
diff --git a/src/utils/mutex.h b/src/utils/mutex.h
new file mode 100644
index 00000000..721bf241
--- /dev/null
+++ b/src/utils/mutex.h
@@ -0,0 +1,41 @@
+// mutex.h
+
+#ifdef __QT_DRIVER__
+#include <QMutex>
+#if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
+#include <QRecursiveMutex>
+#endif
+#endif
+
+namespace FCEU
+{
+	class mutex
+	{
+		public:
+			mutex(void);
+			~mutex(void);
+	
+			void lock(void);
+			void unlock(void);
+	
+		private:
+	#ifdef __QT_DRIVER__
+		#if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
+			QRecursiveMutex *mtx;
+		#else
+			QMutex *mtx;
+		#endif
+	#endif
+	};
+
+	class autoScopedLock
+	{
+		public:
+			autoScopedLock( mutex *mtx );
+			~autoScopedLock(void);
+
+		private:
+			mutex *m;
+	};
+
+};
diff --git a/vc/vc14_fceux.vcxproj b/vc/vc14_fceux.vcxproj
index 1e65fb9c..15d1d650 100644
--- a/vc/vc14_fceux.vcxproj
+++ b/vc/vc14_fceux.vcxproj
@@ -743,6 +743,7 @@ xcopy /y /d "$(ProjectDir)\..\src\drivers\win\7z_64.dll" "$(OutDir)"</Command>
     <ClCompile Include="..\src\utils\ioapi.cpp" />
     <ClCompile Include="..\src\utils\md5.cpp" />
     <ClCompile Include="..\src\utils\memory.cpp" />
+    <ClCompile Include="..\src\utils\mutex.cpp" />
     <ClCompile Include="..\src\utils\unzip.cpp" />
     <ClCompile Include="..\src\utils\xstring.cpp" />
     <ClCompile Include="..\src\lua\src\lapi.c">
@@ -1145,6 +1146,7 @@ xcopy /y /d "$(ProjectDir)\..\src\drivers\win\7z_64.dll" "$(OutDir)"</Command>
     <ClInclude Include="..\src\utils\ioapi.h" />
     <ClInclude Include="..\src\utils\md5.h" />
     <ClInclude Include="..\src\utils\memory.h" />
+    <ClInclude Include="..\src\utils\mutex.h" />
     <ClInclude Include="..\src\utils\unzip.h" />
     <ClInclude Include="..\src\utils\valuearray.h" />
     <ClInclude Include="..\src\utils\xstring.h" />
@@ -1535,4 +1537,4 @@ xcopy /y /d "$(ProjectDir)\..\src\drivers\win\7z_64.dll" "$(OutDir)"</Command>
     </VisualStudio>
   </ProjectExtensions>
   <!-- ================ UNDUPOBJ ================ -->
-</Project>
\ No newline at end of file
+</Project>