diff --git a/bip-DLEQ/reference.py b/bip-DLEQ/reference.py
index 231617ac..ac431985 100644
--- a/bip-DLEQ/reference.py
+++ b/bip-DLEQ/reference.py
@@ -25,11 +25,11 @@ def xor_bytes(lhs: bytes, rhs: bytes) -> bytes:
 
 
 def dleq_challenge(
-    A: GE, B: GE, C: GE, R1: GE, R2: GE, G: GE = G, m: bytes | None = None
+    A: GE, B: GE, C: GE, R1: GE, R2: GE, m: bytes | None, G: GE = G,
 ) -> int:
     if m is not None:
         assert len(m) == 32
-    m = bytes([]) if m is None else m.to_bytes(32, "big")
+    m = bytes([]) if m is None else m
     return int.from_bytes(
         TaggedHash(
             DLEQ_TAG_CHALLENGE,
@@ -64,10 +64,10 @@ def dleq_generate_proof(
         return None
     R1 = k * G
     R2 = k * B
-    e = dleq_challenge(A, B, C, R1, R2)
+    e = dleq_challenge(A, B, C, R1, R2, m)
     s = (k + e * a) % GE.ORDER
     proof = e.to_bytes(32, "big") + s.to_bytes(32, "big")
-    if not dleq_verify_proof(A, B, C, proof):
+    if not dleq_verify_proof(A, B, C, proof, m=m):
         return None
     return proof
 
@@ -87,7 +87,7 @@ def dleq_verify_proof(
     R2 = s * B + (-e * C)
     if R2.infinity:
         return False
-    if e != dleq_challenge(A, B, C, R1, R2):
+    if e != dleq_challenge(A, B, C, R1, R2, m):
         return False
     return True