diff --git a/library/bignum_core.c b/library/bignum_core.c
index 457405d..a3547bd 100644
--- a/library/bignum_core.c
+++ b/library/bignum_core.c
@@ -511,8 +511,8 @@
     mbedtls_ct_mpi_uint_cond_assign( AN_limbs, X, T, (unsigned char) ( carry ^ borrow ) );
 }
 
-int mbedtls_mpi_get_montgomery_constant_unsafe( mbedtls_mpi *X,
-                                                mbedtls_mpi const *N )
+int mbedtls_mpi_core_get_mont_R2_unsafe( mbedtls_mpi *X,
+                                         mbedtls_mpi const *N )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
diff --git a/library/bignum_core.h b/library/bignum_core.h
index 3100bd5..57f27dd 100644
--- a/library/bignum_core.h
+++ b/library/bignum_core.h
@@ -428,7 +428,7 @@
  * \return        #MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED \p N, \p X are NULL
  *                or other operations fail.
  */
-int mbedtls_mpi_get_montgomery_constant_unsafe( mbedtls_mpi *X,
-                                                mbedtls_mpi const *N );
+int mbedtls_mpi_core_get_mont_R2_unsafe( mbedtls_mpi *X,
+                                         mbedtls_mpi const *N );
 
 #endif /* MBEDTLS_BIGNUM_CORE_H */