diff --git a/ai_edge_quantizer/model_validator.py b/ai_edge_quantizer/model_validator.py
index 7ec9bdf..b9fbe21 100644
--- a/ai_edge_quantizer/model_validator.py
+++ b/ai_edge_quantizer/model_validator.py
@@ -224,7 +224,7 @@ def _setup_validation_interpreter(
   """
 
   interpreter = utils.create_tfl_interpreter(
-      tflite_model=model, use_reference_kernel=use_reference_kernel
+      tflite_model=model
   )
   utils.invoke_interpreter_signature(
       interpreter, signature_input, signature_key
diff --git a/ai_edge_quantizer/utils/tfl_interpreter_utils.py b/ai_edge_quantizer/utils/tfl_interpreter_utils.py
index 4d46874..f064e1b 100644
--- a/ai_edge_quantizer/utils/tfl_interpreter_utils.py
+++ b/ai_edge_quantizer/utils/tfl_interpreter_utils.py
@@ -30,15 +30,16 @@
 def create_tfl_interpreter(
     tflite_model: Union[str, bytes],
     allocate_tensors: bool = True,
-    use_reference_kernel: bool = False,
+    use_xnnpack: bool = True,
+    num_threads: int = 4,
 ) -> tfl.Interpreter:
   """Creates a TFLite interpreter from a model file.
 
   Args:
     tflite_model: Model file path or bytes.
     allocate_tensors: Whether to allocate tensors.
-    use_reference_kernel: Whether to use the reference kernel for the
-      interpreter.
+    use_xnnpack: Whether to use the XNNPACK delegate for the interpreter.
+    num_threads: The number of threads to use for the interpreter.
 
   Returns:
     A TFLite interpreter.
@@ -47,12 +48,14 @@ def create_tfl_interpreter(
     with gfile.GFile(tflite_model, "rb") as f:
       tflite_model = f.read()
 
-  if use_reference_kernel:
-    op_resolver = tfl.OpResolverType.BUILTIN_REF
+  if use_xnnpack:
+    op_resolver = tfl.OpResolverType.BUILTIN_WITH_XNNPACK
   else:
     op_resolver = tfl.OpResolverType.BUILTIN_WITHOUT_DEFAULT_DELEGATES
+
   tflite_interpreter = tfl.Interpreter(
       model_content=bytes(tflite_model),
+      num_threads=num_threads,
       experimental_op_resolver_type=op_resolver,
       experimental_preserve_all_tensors=True,
   )