Index: src/loadext.c
==================================================================
--- src/loadext.c
+++ src/loadext.c
@@ -494,12 +494,17 @@
 
   handle = sqlite3OsDlOpen(pVfs, zFile);
 #if SQLITE_OS_UNIX || SQLITE_OS_WIN
   for(ii=0; ii<ArraySize(azEndings) && handle==0; ii++){
     char *zAltFile = sqlite3_mprintf("%s.%s", zFile, azEndings[ii]);
+    int bOk = 0;
     if( zAltFile==0 ) return SQLITE_NOMEM_BKPT;
-    handle = sqlite3OsDlOpen(pVfs, zAltFile);
+    if( sqlite3OsAccess(pVfs,zAltFile,SQLITE_ACCESS_EXISTS,&bOk)==SQLITE_OK
+     && bOk
+    ){
+      handle = sqlite3OsDlOpen(pVfs, zAltFile);
+    }
     sqlite3_free(zAltFile);
   }
 #endif
   if( handle==0 ){
     if( pzErrMsg ){