diff --git a/wolfcrypt/__init__.py b/wolfcrypt/__init__.py
index dccbda3..1b15dae 100644
--- a/wolfcrypt/__init__.py
+++ b/wolfcrypt/__init__.py
@@ -18,6 +18,10 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
 
+import os
+import sys
+from typing import TYPE_CHECKING
+
 from wolfcrypt._version import __version__, __wolfssl_version__
 
 __title__ = "wolfcrypt"
@@ -36,9 +40,6 @@ __all__ = [
     "ciphers", "hashes", "random", "pwdbased", "cryptocb"
 ]
 
-import os
-import sys
-
 top_level_py = os.path.basename(sys.argv[0])
 
 # The code below is intended to only be used after the CFFI is built, so we
@@ -46,8 +47,10 @@ top_level_py = os.path.basename(sys.argv[0])
 if top_level_py not in ["setup.py", "build_ffi.py"]:
     from wolfcrypt._ffi import ffi as _ffi
     from wolfcrypt._ffi import lib as _lib
-    if _lib.CRYPTO_CB_ENABLED:
-        from wolfcrypt.cryptocb import CryptoCallback
+
+    if TYPE_CHECKING:
+        if _lib.CRYPTO_CB_ENABLED:
+            from wolfcrypt.cryptocb import CryptoCallback
     from wolfcrypt.exceptions import WolfCryptApiError
 
     ret = _lib.wolfCrypt_Init()
diff --git a/wolfcrypt/_ffi/lib.pyi b/wolfcrypt/_ffi/lib.pyi
index ca50324..d08d444 100644
--- a/wolfcrypt/_ffi/lib.pyi
+++ b/wolfcrypt/_ffi/lib.pyi
@@ -18,9 +18,12 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 
-from _cffi_backend import FFI
+from collections.abc import Callable
+from dataclasses import dataclass
 from typing import TypeAlias
 
+from _cffi_backend import FFI
+
 INVALID_DEVID: int
 
 AES_ENABLED: int
@@ -30,6 +33,7 @@ ASN_ENABLED: int
 CHACHA_ENABLED: int
 CHACHA_STREAM_ENABLED: int
 CHACHA20_POLY1305_ENABLED: int
+CRYPTO_CB_ENABLED: int
 DES3_ENABLED: int
 ECC_ENABLED: int
 ED25519_ENABLED: int
@@ -282,6 +286,20 @@ WC_MGF1SHA256: int
 WC_MGF1SHA384: int
 WC_MGF1SHA512: int
 
+WC_ALGO_TYPE_NONE: int
+WC_ALGO_TYPE_HASH: int
+WC_ALGO_TYPE_CIPHER: int
+WC_ALGO_TYPE_PK: int
+WC_ALGO_TYPE_RNG: int
+WC_ALGO_TYPE_SEED: int
+WC_ALGO_TYPE_HMAC: int
+WC_ALGO_TYPE_CMAC: int
+WC_ALGO_TYPE_CERT: int
+WC_ALGO_TYPE_KDF: int
+WC_ALGO_TYPE_COPY: int
+WC_ALGO_TYPE_FREE: int
+WC_ALGO_TYPE_MAX: int
+
 WC_HASH_TYPE_NONE: int
 WC_HASH_TYPE_MD2: int
 WC_HASH_TYPE_MD4: int
@@ -328,6 +346,7 @@ RNG: TypeAlias = FFI.CData
 def wc_SetSeed_Cb(cb: FFI.CData) -> int: ...
 def wolfCrypt_SetPrivateKeyReadEnable_fips(enable: int, key_type: int) -> int: ...
 def wc_GetErrorString(error: int) -> FFI.CData: ...
+def wolfCrypt_Init() -> int: ...
 
 def wc_InitRngNonce_ex(rng: RNG, nonce: bytes, nonce_size: int, heap: FFI.CData, device_id: int) -> int: ...
 def wc_RNG_GenerateByte(rng: RNG, buffer: FFI.CData) -> int: ...
@@ -569,3 +588,36 @@ def wc_dilithium_sign_msg_with_seed(msg: bytes, msg_len: int, sig: BytePtr, sig_
 def wc_MlDsaKey_GetPrivLen(key: DilithiumKey, len: IntPtr) -> int: ...
 def wc_MlDsaKey_GetPubLen(key: DilithiumKey, len: IntPtr) -> int: ...
 def wc_MlDsaKey_GetSigLen(key: DilithiumKey, len: IntPtr) -> int: ...
+
+@dataclass
+class wc_HashInfo:
+    type: int
+    data: FFI.CData
+    data_size: int
+    digest: FFI.CData
+    sha: FFI.CData
+    sha256: FFI.CData
+    sha384: FFI.CData
+    sha512: FFI.CData
+    sha3: FFI.CData
+    ctx: FFI.CData
+
+
+@dataclass
+class wc_RngInfo:
+    rng: RNG
+    out: FFI.CData
+    sz: int
+
+
+@dataclass
+class wc_CryptoInfo:
+    algo_type: int
+    hash: wc_HashInfo
+    rng: wc_RngInfo
+
+
+def wc_CryptoCb_RegisterDevice(dev_id: int, cb: Callable[[int, wc_CryptoInfo, FFI.CData], int], ctx: FFI.CData) -> int: ...
+def wc_CryptoCb_UnRegisterDevice(dev_id: int) -> None: ...
+def wc_CryptoCb_DefaultDevID() -> int: ...
+def py_wc_crypto_callback(dev_id: int, info: wc_CryptoInfo, ctx: FFI.CData) -> int: ...
diff --git a/wolfcrypt/cryptocb.py b/wolfcrypt/cryptocb.py
index 566c762..89f6a05 100644
--- a/wolfcrypt/cryptocb.py
+++ b/wolfcrypt/cryptocb.py
@@ -24,8 +24,7 @@ from __future__ import annotations
 
 import logging
 from collections import defaultdict
-from types import TracebackType
-from typing import Final
+from typing import TYPE_CHECKING, Final
 
 from typing_extensions import Self
 
@@ -33,6 +32,9 @@ from wolfcrypt._ffi import ffi as _ffi
 from wolfcrypt._ffi import lib as _lib
 from wolfcrypt.exceptions import WolfCryptError
 
+if TYPE_CHECKING:
+    from types import TracebackType
+
 log = logging.getLogger(__name__)
 
 if _lib.CRYPTO_CB_ENABLED:
@@ -100,7 +102,7 @@ if _lib.CRYPTO_CB_ENABLED:
         def __del__(self) -> None:
             self._unregister()
 
-        def callback(self, device_id: int, info: _ffi.CData) -> int:
+        def callback(self, device_id: int, info: _lib.wc_CryptoInfo) -> int:
             log.debug("device_id=%d algo_type = %s", device_id, ALGO_TYPE_NAME[info.algo_type])
             try:
                 if info.algo_type == _lib.WC_ALGO_TYPE_HASH:
@@ -137,7 +139,7 @@ if _lib.CRYPTO_CB_ENABLED:
             except NotImplementedError:
                 return _lib.CRYPTOCB_UNAVAILABLE
 
-        def rng_callback(self, device_id: int, rng, size: int) -> bytes:
+        def rng_callback(self, device_id: int, rng: _lib.RNG, size: int) -> bytes:
             raise NotImplementedError
 
         def hash_update_callback(self, device_id: int, hash_type: int, data: bytes) -> None: