diff --git a/bip-0352/secp256k1.py b/bip-0352/secp256k1.py
index 0ccbc4e6a4..738f32925a 100644
--- a/bip-0352/secp256k1.py
+++ b/bip-0352/secp256k1.py
@@ -373,7 +373,7 @@ def verify_ecdsa(self, sig, msg, low_s=True):
         u1 = z*w % SECP256K1_ORDER
         u2 = r*w % SECP256K1_ORDER
         R = SECP256K1.affine(SECP256K1.mul([(SECP256K1_G, u1), (self.p, u2)]))
-        if R is None or R[0] != r:
+        if R is None or (R[0] % SECP256K1_ORDER) != r:
             return False
         return True