Index: src/os_win.c
==================================================================
--- src/os_win.c
+++ src/os_win.c
@@ -5409,18 +5409,18 @@
 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
   if( sizeof(UUID)<=nBuf-n ){
     UUID id;
     memset(&id, 0, sizeof(UUID));
     osUuidCreate(&id);
-    memcpy(zBuf, &id, sizeof(UUID));
+    memcpy(&zBuf[n], &id, sizeof(UUID));
     n += sizeof(UUID);
   }
   if( sizeof(UUID)<=nBuf-n ){
     UUID id;
     memset(&id, 0, sizeof(UUID));
     osUuidCreateSequential(&id);
-    memcpy(zBuf, &id, sizeof(UUID));
+    memcpy(&zBuf[n], &id, sizeof(UUID));
     n += sizeof(UUID);
   }
 #endif
 #endif /* defined(SQLITE_TEST) || defined(SQLITE_ZERO_PRNG_SEED) */
   return n;