diff --git a/src/local_bip85/__init__.py b/src/local_bip85/__init__.py
index 36da833..e1f44b1 100644
--- a/src/local_bip85/__init__.py
+++ b/src/local_bip85/__init__.py
@@ -6,10 +6,10 @@ logger = logging.getLogger(__name__)
 
 try:
     from .bip85 import BIP85
+except Exception as exc:
+    logger.error("Failed to import BIP85 module: %s", exc, exc_info=True)
+    raise ImportError(
+        "BIP85 dependencies are missing. Install 'bip_utils', 'cryptography', and 'colorama'."
+    ) from exc
 
-    logger.info("BIP85 module imported successfully.")
-except Exception as e:
-    logger.error(f"Failed to import BIP85 module: {e}", exc_info=True)
-    BIP85 = None
-
-__all__ = ["BIP85"] if BIP85 is not None else []
+__all__ = ["BIP85"]
diff --git a/src/local_bip85/bip85.py b/src/local_bip85/bip85.py
index 665b5f3..52b270e 100644
--- a/src/local_bip85/bip85.py
+++ b/src/local_bip85/bip85.py
@@ -18,6 +18,8 @@ import hashlib
 import hmac
 import logging
 import os
+from typing import Union
+
 from colorama import Fore
 
 from bip_utils import Bip32Slip10Secp256k1, Bip39MnemonicGenerator, Bip39Languages
@@ -37,13 +39,19 @@ class Bip85Error(Exception):
 
 
 class BIP85:
-    def __init__(self, seed_bytes: bytes | str):
-        """Initialize from BIP39 seed bytes or BIP32 xprv string."""
+    def __init__(self, seed_or_xprv: Union[bytes, str]):
+        """Initialize from seed bytes or an ``xprv`` string.
+
+        Parameters:
+            seed_or_xprv (Union[bytes, str]): Either raw BIP39 seed bytes
+                or a BIP32 extended private key (``xprv``) string.
+        """
+
         try:
-            if isinstance(seed_bytes, (bytes, bytearray)):
-                self.bip32_ctx = Bip32Slip10Secp256k1.FromSeed(seed_bytes)
+            if isinstance(seed_or_xprv, (bytes, bytearray)):
+                self.bip32_ctx = Bip32Slip10Secp256k1.FromSeed(seed_or_xprv)
             else:
-                self.bip32_ctx = Bip32Slip10Secp256k1.FromExtendedKey(seed_bytes)
+                self.bip32_ctx = Bip32Slip10Secp256k1.FromExtendedKey(seed_or_xprv)
             logging.debug("BIP32 context initialized successfully.")
         except Exception as e:
             logging.error(f"Error initializing BIP32 context: {e}", exc_info=True)
diff --git a/src/tests/test_bip85_init.py b/src/tests/test_bip85_init.py
new file mode 100644
index 0000000..5f12b37
--- /dev/null
+++ b/src/tests/test_bip85_init.py
@@ -0,0 +1,21 @@
+import sys
+from pathlib import Path
+
+sys.path.append(str(Path(__file__).resolve().parents[1]))
+
+from bip_utils import Bip39SeedGenerator
+from local_bip85.bip85 import BIP85
+from helpers import TEST_SEED
+
+MASTER_XPRV = "xprv9s21ZrQH143K2LBWUUQRFXhucrQqBpKdRRxNVq2zBqsx8HVqFk2uYo8kmbaLLHRdqtQpUm98uKfu3vca1LqdGhUtyoFnCNkfmXRyPXLjbKb"
+
+
+def test_init_with_seed_bytes():
+    seed_bytes = Bip39SeedGenerator(TEST_SEED).Generate()
+    bip85 = BIP85(seed_bytes)
+    assert isinstance(bip85, BIP85)
+
+
+def test_init_with_xprv():
+    bip85 = BIP85(MASTER_XPRV)
+    assert isinstance(bip85, BIP85)
diff --git a/src/utils/key_derivation.py b/src/utils/key_derivation.py
index ca15423..aed72cf 100644
--- a/src/utils/key_derivation.py
+++ b/src/utils/key_derivation.py
@@ -23,7 +23,9 @@ import hmac
 import time
 from enum import Enum
 from typing import Optional, Union
+
 from bip_utils import Bip39SeedGenerator
+from local_bip85 import BIP85
 
 from cryptography.hazmat.primitives.kdf.hkdf import HKDF
 from cryptography.hazmat.primitives import hashes
@@ -213,8 +215,6 @@ def derive_index_key(seed: str) -> bytes:
 def derive_totp_secret(seed: str, index: int) -> str:
     """Derive a base32-encoded TOTP secret from a BIP39 seed."""
     try:
-        from local_bip85 import BIP85
-
         # Initialize BIP85 from the BIP39 seed bytes
         seed_bytes = Bip39SeedGenerator(seed).Generate()
         bip85 = BIP85(seed_bytes)