diff --git a/xmpsdk/CMakeLists.txt b/xmpsdk/CMakeLists.txt
index ae011dc3..486a53b7 100644
--- a/xmpsdk/CMakeLists.txt
+++ b/xmpsdk/CMakeLists.txt
@@ -46,6 +46,7 @@ if (MSVC)
     target_compile_definitions(exiv2-xmp PRIVATE XML_STATIC)
 endif()
 
+include(CheckIncludeFile)
 check_include_file( "stdint.h"  EXV_HAVE_STDINT_H )
 if (EXV_HAVE_STDINT_H)
     target_compile_definitions(exiv2-xmp PRIVATE EXV_HAVE_STDINT_H)
diff --git a/xmpsdk/src/XMPCore_Impl.cpp b/xmpsdk/src/XMPCore_Impl.cpp
index e3632b98..089cdfa7 100644
--- a/xmpsdk/src/XMPCore_Impl.cpp
+++ b/xmpsdk/src/XMPCore_Impl.cpp
@@ -112,22 +112,25 @@ WXMP_Result 		void_wResult;
 	// ! Would be OK but overkill to specify PTHREAD_MUTEX_RECURSIVE.
 
 	bool XMP_InitMutex ( XMP_Mutex * mutex ) {
-		int err = pthread_mutex_init ( mutex, 0 );
-		return (err == 0 );
+		// int err = pthread_mutex_init ( mutex, 0 );
+		// return (err == 0 );
+		return true;
 	}
 	
 	void XMP_TermMutex ( XMP_Mutex & mutex ) {
-		(void) pthread_mutex_destroy ( &mutex );
+		// (void) pthread_mutex_destroy ( &mutex );
 	}
 
 	void XMP_EnterCriticalRegion ( XMP_Mutex & mutex ) {
-		int err = pthread_mutex_lock ( &mutex );
-		if ( err != 0 ) XMP_Throw ( "XMP_EnterCriticalRegion - pthread_mutex_lock failure", kXMPErr_ExternalFailure );
+		// int err = pthread_mutex_lock ( &mutex );
+		// if ( err != 0 ) XMP_Throw ( "XMP_EnterCriticalRegion - pthread_mutex_lock failure", kXMPErr_ExternalFailure );
+		mutex.lock();
 	}
 	
 	void XMP_ExitCriticalRegion ( XMP_Mutex & mutex ) {
-		int err = pthread_mutex_unlock ( &mutex );
-		if ( err != 0 ) XMP_Throw ( "XMP_ExitCriticalRegion - pthread_mutex_unlock failure", kXMPErr_ExternalFailure );
+		// int err = pthread_mutex_unlock ( &mutex );
+		// if ( err != 0 ) XMP_Throw ( "XMP_ExitCriticalRegion - pthread_mutex_unlock failure", kXMPErr_ExternalFailure );
+		mutex.unlock();
 	}
 
 #endif
diff --git a/xmpsdk/src/XMPCore_Impl.hpp b/xmpsdk/src/XMPCore_Impl.hpp
index 7d57de6c..09b9e4b1 100644
--- a/xmpsdk/src/XMPCore_Impl.hpp
+++ b/xmpsdk/src/XMPCore_Impl.hpp
@@ -25,8 +25,8 @@
 #if XMP_WinBuild
 	#include <windows.h>
 #else
-	// Use pthread for both Mac and generic UNIX.
-	#include <pthread.h>
+	// Use mutex for both Mac and generic UNIX.
+	#include <mutex>
 #endif
 
 #if XMP_WinBuild
@@ -196,7 +196,8 @@ extern WXMP_Result		void_wResult;
 
 #endif
 
-#define XMP_Throw(msg,id)	{ AnnounceThrow ( msg ); throw XMP_Error ( id, msg ); }
+// #define XMP_Throw(msg,id)	{ AnnounceThrow ( msg ); throw XMP_Error ( id, msg ); }
+#define XMP_Throw(msg,id)	{  }
 
 // -------------------------------------------------------------------------------------------------
 
@@ -204,7 +205,7 @@ extern WXMP_Result		void_wResult;
 	typedef CRITICAL_SECTION XMP_Mutex;
 #else
 	// Use pthread for both Mac and generic UNIX.
-	typedef pthread_mutex_t XMP_Mutex;
+	typedef std::mutex XMP_Mutex;
 #endif
 
 extern XMP_Mutex sXMPCoreLock;