diff --git a/src/arclet/alconna/sistana/analyzer.py b/src/arclet/alconna/sistana/analyzer.py
index 235f238..4e77687 100644
--- a/src/arclet/alconna/sistana/analyzer.py
+++ b/src/arclet/alconna/sistana/analyzer.py
@@ -84,16 +84,17 @@ def loopflow(self, snapshot: AnalyzeSnapshot[T], buffer: Buffer[T]) -> LoopflowE
                 return LoopflowExitReason.unsatisfied
 
             if pointer_type is PointerRole.PREFIX:
-                if not isinstance(token.val, str):
-                    return LoopflowExitReason.header_expect_str
-
                 if context.prefixes is not None:
-                    prefix = context.prefixes.get_closest_prefix(buffer.first())  # type: ignore
-                    if prefix == "":
-                        return LoopflowExitReason.prefix_mismatch
+                    if not isinstance(token.val, str):
+                        return LoopflowExitReason.header_expect_str
+
+                    if context.prefixes is not None:
+                        prefix = context.prefixes.get_closest_prefix(buffer.first())  # type: ignore
+                        if prefix == "":
+                            return LoopflowExitReason.prefix_mismatch
 
-                    token.apply()
-                    buffer.pushleft(token.val[len(prefix) :])
+                        token.apply()
+                        buffer.pushleft(token.val[len(prefix) :])
 
                 traverse.ref = traverse.ref.parent.header()  # 直接进 header.
             elif pointer_type is PointerRole.HEADER:
diff --git a/src/arclet/alconna/sistana/model/pattern.py b/src/arclet/alconna/sistana/model/pattern.py
index ec83528..4313ccd 100644
--- a/src/arclet/alconna/sistana/model/pattern.py
+++ b/src/arclet/alconna/sistana/model/pattern.py
@@ -51,7 +51,6 @@ def build(
         subcommand = cls(
             header=header,
             preset=Preset(),
-            prefixes=TrieHard(list(prefixes)),
             compact_header=compact_header,
             satisfy_previous=satisfy_previous,
             separators=separators,
@@ -60,6 +59,9 @@ def build(
         )
         subcommand.add_track(header, fragments, header=header_fragment)
 
+        if prefixes:
+            subcommand.prefixes = TrieHard(list(prefixes))
+
         return subcommand
 
     @property