diff --git a/python/.changelog.d/2126.changed b/python/.changelog.d/2126.changed
new file mode 100644
index 0000000000..6ea3e552a2
--- /dev/null
+++ b/python/.changelog.d/2126.changed
@@ -0,0 +1 @@
+Rename `normalize_nfc` to `prepare_message_bytes` in tools.py
diff --git a/python/src/trezorlib/btc.py b/python/src/trezorlib/btc.py
index 29647bc4cf..30e98aa05f 100644
--- a/python/src/trezorlib/btc.py
+++ b/python/src/trezorlib/btc.py
@@ -23,7 +23,7 @@ from typing import TYPE_CHECKING, Any, AnyStr, List, Optional, Sequence, Tuple
 from typing_extensions import Protocol, TypedDict
 
 from . import exceptions, messages
-from .tools import expect, normalize_nfc, session
+from .tools import expect, prepare_message_bytes, session
 
 if TYPE_CHECKING:
     from .client import TrezorClient
@@ -219,7 +219,7 @@ def sign_message(
         messages.SignMessage(
             coin_name=coin_name,
             address_n=n,
-            message=normalize_nfc(message),
+            message=prepare_message_bytes(message),
             script_type=script_type,
             no_script_type=no_script_type,
         )
@@ -238,7 +238,7 @@ def verify_message(
             messages.VerifyMessage(
                 address=address,
                 signature=signature,
-                message=normalize_nfc(message),
+                message=prepare_message_bytes(message),
                 coin_name=coin_name,
             )
         )
diff --git a/python/src/trezorlib/ethereum.py b/python/src/trezorlib/ethereum.py
index 098dbecc2c..01a9d543cc 100644
--- a/python/src/trezorlib/ethereum.py
+++ b/python/src/trezorlib/ethereum.py
@@ -18,7 +18,7 @@ import re
 from typing import TYPE_CHECKING, Any, AnyStr, Dict, List, Optional, Tuple
 
 from . import exceptions, messages
-from .tools import expect, normalize_nfc, session
+from .tools import expect, prepare_message_bytes, session
 
 if TYPE_CHECKING:
     from .client import TrezorClient
@@ -268,7 +268,9 @@ def sign_message(
     client: "TrezorClient", n: "Address", message: AnyStr
 ) -> "MessageType":
     return client.call(
-        messages.EthereumSignMessage(address_n=n, message=normalize_nfc(message))
+        messages.EthereumSignMessage(
+            address_n=n, message=prepare_message_bytes(message)
+        )
     )
 
 
@@ -351,7 +353,9 @@ def verify_message(
     try:
         resp = client.call(
             messages.EthereumVerifyMessage(
-                address=address, signature=signature, message=normalize_nfc(message)
+                address=address,
+                signature=signature,
+                message=prepare_message_bytes(message),
             )
         )
     except exceptions.TrezorFailure:
diff --git a/python/src/trezorlib/tools.py b/python/src/trezorlib/tools.py
index 961f652161..67f8115ff4 100644
--- a/python/src/trezorlib/tools.py
+++ b/python/src/trezorlib/tools.py
@@ -211,13 +211,15 @@ def parse_path(nstr: str) -> Address:
         raise ValueError("Invalid BIP32 path", nstr) from e
 
 
-def normalize_nfc(txt: AnyStr) -> bytes:
+def prepare_message_bytes(txt: AnyStr) -> bytes:
     """
-    Normalize message to NFC and return bytes suitable for protobuf.
-    This seems to be bitcoin-qt standard of doing things.
+    Make message suitable for protobuf.
+    If the message is a Unicode string, normalize it.
+    If it's bytes, return the raw bytes.
     """
-    str_txt = txt.decode() if isinstance(txt, bytes) else txt
-    return unicodedata.normalize("NFC", str_txt).encode()
+    if isinstance(txt, bytes):
+        return txt
+    return unicodedata.normalize("NFC", txt).encode()
 
 
 # NOTE for type tests (mypy/pyright):