diff --git a/library/ecp_invasive.h b/library/ecp_invasive.h
index bd6d399..a0d038c 100644
--- a/library/ecp_invasive.h
+++ b/library/ecp_invasive.h
@@ -189,7 +189,7 @@
 #if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
 
 MBEDTLS_STATIC_TESTABLE
-int ecp_mod_p256k1(mbedtls_mpi *N);
+int mbedtls_ecp_mod_p256k1(mbedtls_mpi *N);
 
 #endif /* MBEDTLS_ECP_DP_SECP256K1_ENABLED */