diff --git a/onnxscript/rewriter/__init__.py b/onnxscript/rewriter/__init__.py
index ea5c823a9..7dc784650 100644
--- a/onnxscript/rewriter/__init__.py
+++ b/onnxscript/rewriter/__init__.py
@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import Sequence
+from typing import Sequence, Union
 
 __all__ = [
     # Modules
@@ -16,6 +16,7 @@
 from onnxscript.optimizer import remove_unused, remove_unused_function
 from onnxscript.rewriter import function_rule, pattern
 
+RewriteRuleSet = pattern.RewriteRuleSet
 PatternRewriteRule = pattern.RewriteRule
 FunctionRewriteRule = function_rule.FunctionRewriteRule
 
@@ -23,7 +24,7 @@
 def rewrite(
     model: onnx.ModelProto,
     function_rewrite_rules: Sequence[type[FunctionRewriteRule]] = (),
-    pattern_rewrite_rules: Sequence[PatternRewriteRule] = (),
+    pattern_rewrite_rules: Union[Sequence[PatternRewriteRule], RewriteRuleSet] = (),
 ) -> onnx.ModelProto:
     model_ir = ir.serde.deserialize_model(model)
     if function_rewrite_rules:
@@ -31,7 +32,10 @@ def rewrite(
             count, model_ir = rule_cls().apply_to_model(model_ir)
             print(f"Applied {count} of onnxruntime specific function rewrite rules.")
     if pattern_rewrite_rules:
-        count = pattern.RewriteRuleSet(pattern_rewrite_rules).apply_to_model(model_ir)
+        if not isinstance(pattern_rewrite_rules, RewriteRuleSet):
+            # Create a pattern rule-set using provided rules
+            pattern_rewrite_rules = pattern.RewriteRuleSet(pattern_rewrite_rules)
+        count = pattern_rewrite_rules.apply_to_model(model_ir)
         print(f"Applied {count} of general pattern rewrite rules.")
     model = ir.serde.serialize_model(model_ir)
     remove_unused.remove_unused_nodes(model)