diff --git a/doc/env_cn.md b/doc/env_cn.md
index 8a05e2f..8239ab0 100644
--- a/doc/env_cn.md
+++ b/doc/env_cn.md
@@ -196,7 +196,7 @@ import mlvp
 
 mlvp.debug("This is a debug message", extra={"log_id": "dut"})
 mlvp.info("This is an info message")
-mlvp.warning("This is a warning message", extra={"log_id": "interface"})
+mlvp.warning("This is a warning message", extra={"log_id": "bundle"})
 mlvp.error("This is an error message")
 mlvp.critical("This is a critical message")
 ```
diff --git a/tests/uFTB-with-ftq/env/bundle.py b/tests/uFTB-with-ftq/env/bundle.py
index 69c63e1..200d473 100644
--- a/tests/uFTB-with-ftq/env/bundle.py
+++ b/tests/uFTB-with-ftq/env/bundle.py
@@ -1,6 +1,6 @@
-from mlvp import Interface
+from mlvp import Bundle
 
-class PipelineCtrlBundle(Interface):
+class PipelineCtrlBundle(Bundle):
     signals_list = ["s0_fire_0", "s0_fire_1", "s0_fire_2", "s0_fire_3",
                     "s1_fire_0", "s1_fire_1", "s1_fire_2", "s1_fire_3",
                     "s2_fire_0", "s2_fire_1", "s2_fire_2", "s2_fire_3",
@@ -8,25 +8,25 @@ class PipelineCtrlBundle(Interface):
                     "s1_ready", "s2_ready", "s3_ready",
                     "s2_redirect", "s3_redirect"]
 
-class EnableCtrlBundle(Interface):
+class EnableCtrlBundle(Bundle):
     signals_list = ["ubtb_enable", "btb_enable", "bim_enable", "tage_enable",
                     "sc_enable", "ras_enable", "loop_enable"]
 
 
-class FTBEntryBundle(Interface):
+class FTBEntryBundle(Bundle):
     signals_list = ["brSlots_0_offset", "brSlots_0_lower", "brSlots_0_tarStat", "brSlots_0_valid",
                     "tailSlot_offset", "tailSlot_lower", "tailSlot_tarStat", "tailSlot_sharing", "tailSlot_valid",
                     "pftAddr", "carry", "isCall", "isRet", "isJalr", "last_may_be_rvi_call",
                      "always_taken_0", "always_taken_1"]
 
-class UpdateBundle(Interface):
+class UpdateBundle(Bundle):
     signals_list = ["valid", "bits_pc", "bits_br_taken_mask_0", "bits_br_taken_mask_1"]
 
-    sub_interfaces = [
+    sub_bundles = [
         ("ftb_entry", lambda dut: FTBEntryBundle.from_prefix(dut, "bits_ftb_entry_"))
     ]
 
-class FullBranchPredirectionBundle(Interface):
+class FullBranchPredirectionBundle(Bundle):
     signals_list = ["hit", "slot_valids_0", "slot_valids_1", "targets_0", "targets_1",
                     "offsets_0", "offsets_1", "fallThroughAddr", "fallThroughErr",
                     "is_jal", "is_jalr", "is_call", "is_ret", "is_br_sharing",
@@ -34,16 +34,16 @@ class FullBranchPredirectionBundle(Interface):
                     "br_taken_mask_0", "br_taken_mask_1",
                     "jalr_target"]
 
-class BranchPredictionBundle(Interface):
+class BranchPredictionBundle(Bundle):
     signals_list = ["pc_3", "valid", "hasRedirect", "ftq_idx"]
-    sub_interfaces = [
+    sub_bundles = [
         ("full_pred", lambda dut: FullBranchPredirectionBundle.from_regex(dut, r"full_pred_\d_(.*)"))
     ]
 
 
-class BranchPredictionResp(Interface):
+class BranchPredictionResp(Bundle):
     signals_list = ["last_stage_meta"]
-    sub_interfaces = [
+    sub_bundles = [
         ("s1", lambda dut: BranchPredictionBundle.from_prefix(dut, "s1_")),
         ("s2", lambda dut: BranchPredictionBundle.from_prefix(dut, "s2_")),
         ("s3", lambda dut: BranchPredictionBundle.from_prefix(dut, "s3_")),
diff --git a/tests/uFTB-with-ftq/env/uftb_model.py b/tests/uFTB-with-ftq/env/uftb_model.py
index 0d140a7..7bc1c6f 100644
--- a/tests/uFTB-with-ftq/env/uftb_model.py
+++ b/tests/uFTB-with-ftq/env/uftb_model.py
@@ -1,4 +1,4 @@
-from mlvp.utils import PLRU, TwoBitsCounter
+from mlvp.modules import PLRU, TwoBitsCounter
 from mlvp import *
 from .ftb import *