Index: src/wal.c
==================================================================
--- src/wal.c
+++ src/wal.c
@@ -611,11 +611,11 @@
     flags = (SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_MAIN_JOURNAL);
     rc = sqlite3OsOpen(pVfs, zWal, pRet->pFd, flags, &flags);
   }
 
   if( rc!=SQLITE_OK ){
-    pVfs->xShmClose(pVfs, pRet->pWIndex, 0);
+    if( pRet->pWIndex ) pVfs->xShmClose(pVfs, pRet->pWIndex, 0);
     sqlite3OsClose(pRet->pFd);
     sqlite3_free(pRet);
   }else{
     *ppWal = pRet;
   }