diff --git a/internal/option.go b/internal/option.go
index a262073..c82e6a7 100644
--- a/internal/option.go
+++ b/internal/option.go
@@ -341,11 +341,11 @@ func (opt *Option) PrepareRunner() (*Runner, error) {
 
 	if len(opt.Suffixes) != 0 {
 		mask.SpecialWords["suffix"] = opt.Suffixes
-		opt.Word += "{@suffix}"
+		opt.Word += "{?@suffix}"
 	}
 	if len(opt.Prefixes) != 0 {
 		mask.SpecialWords["prefix"] = opt.Prefixes
-		opt.Word = "{@prefix}" + opt.Word
+		opt.Word = "{?@prefix}" + opt.Word
 	}
 
 	if opt.ForceExtension && opt.Extensions != "" {
@@ -356,7 +356,7 @@ func (opt *Option) PrepareRunner() (*Runner, error) {
 			}
 		}
 		mask.SpecialWords["ext"] = exts
-		opt.Word += "{@ext}"
+		opt.Word += "{?@ext}"
 	}
 
 	r.Wordlist, err = mask.Run(opt.Word, dicts, nil)
diff --git a/internal/pool/brutepool.go b/internal/pool/brutepool.go
index a9e4562..d7d6d84 100644
--- a/internal/pool/brutepool.go
+++ b/internal/pool/brutepool.go
@@ -710,7 +710,7 @@ func (pool *BrutePool) addFuzzyBaseline(bl *pkg.Baseline) {
 
 func (pool *BrutePool) doBak() {
 	defer pool.wg.Done()
-	worder, err := words.NewWorderWithDsl("{?0}.{@bak_ext}", [][]string{pkg.BakGenerator(pool.url.Host)}, nil)
+	worder, err := words.NewWorderWithDsl("{?0}.{?@bak_ext}", [][]string{pkg.BakGenerator(pool.url.Host)}, nil)
 	if err != nil {
 		return
 	}
@@ -722,7 +722,7 @@ func (pool *BrutePool) doBak() {
 		})
 	}
 
-	worder, err = words.NewWorderWithDsl("{@bak_name}.{@bak_ext}", nil, nil)
+	worder, err = words.NewWorderWithDsl("{?@bak_name}.{?@bak_ext}", nil, nil)
 	if err != nil {
 		return
 	}