Index: src/mutex.c
==================================================================
--- src/mutex.c
+++ src/mutex.c
@@ -22,10 +22,22 @@
 ** allocate a mutex while the system is uninitialized.
 */
 static SQLITE_WSD int mutexIsInit = 0;
 #endif /* SQLITE_DEBUG */
 
+/*
+** Implementations can specify an alternative routine for initializing
+** the mutex using the SQLITE_MUTEX_DEFAULT macro.  This macro should
+** resolve to an expression that returns a pointer to an
+** sqlite3_mutex_methods object that implements the default mutex.
+** This is an undocumented feature and may not be supported in future 
+** releases.
+*/
+#if !defined(SQLITE_MUTEX_DEFAULT)
+# define SQLITE_MUTEX_DEFAULT sqlite3DefaultMutex()
+#endif
+
 
 #ifndef SQLITE_MUTEX_OMIT
 /*
 ** Initialize the mutex system.
 */
@@ -39,11 +51,11 @@
     */
     sqlite3_mutex_methods const *pFrom;
     sqlite3_mutex_methods *pTo = &sqlite3GlobalConfig.mutex;
 
     if( sqlite3GlobalConfig.bCoreMutex ){
-      pFrom = sqlite3DefaultMutex();
+      pFrom = SQLITE_MUTEX_DEFAULT;
     }else{
       pFrom = sqlite3NoopMutex();
     }
     memcpy(pTo, pFrom, offsetof(sqlite3_mutex_methods, xMutexAlloc));
     memcpy(&pTo->xMutexFree, &pFrom->xMutexFree,