diff --git a/library/bignum_mod.c b/library/bignum_mod.c
index 54d38bd..60a3c30 100644
--- a/library/bignum_mod.c
+++ b/library/bignum_mod.c
@@ -166,7 +166,8 @@
 int mbedtls_mpi_mod_optred_modulus_setup(mbedtls_mpi_mod_modulus *N,
                                          const mbedtls_mpi_uint *p,
                                          size_t p_limbs,
-                                         int (*modp)(mbedtls_mpi *))
+                                         int (*modp)(mbedtls_mpi_uint *X,
+                                                     size_t X_limbs))
 {
     standard_modulus_setup(N, p, p_limbs, MBEDTLS_MPI_MOD_REP_OPT_RED);
     N->rep.ored.modp = modp;
diff --git a/library/bignum_mod.h b/library/bignum_mod.h
index 60966cc..87ee015 100644
--- a/library/bignum_mod.h
+++ b/library/bignum_mod.h
@@ -125,7 +125,8 @@
 } mbedtls_mpi_mont_struct;
 
 typedef struct {
-    int (*modp)(mbedtls_mpi *);  /* The optimised reduction function pointer */
+    int (*modp)(mbedtls_mpi_uint *X,
+                size_t X_limbs);  /* The optimised reduction function pointer */
 } mbedtls_mpi_opt_red_struct;
 
 typedef struct {
@@ -222,7 +223,8 @@
 int mbedtls_mpi_mod_optred_modulus_setup(mbedtls_mpi_mod_modulus *N,
                                          const mbedtls_mpi_uint *p,
                                          size_t p_limbs,
-                                         int (*modp)(mbedtls_mpi *));
+                                         int (*modp)(mbedtls_mpi_uint *X,
+                                                     size_t X_limbs));
 
 /** Free elements of a modulus structure.
  *
diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index 5692772..cb94196 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -5833,7 +5833,7 @@
                               const mbedtls_ecp_group_id id,
                               const mbedtls_ecp_modulus_type ctype)
 {
-    int (*modp)(mbedtls_mpi *) = NULL;
+    int (*modp)(mbedtls_mpi_uint *X, size_t X_limbs) = NULL;
     mbedtls_mpi_uint *p = NULL;
     size_t p_limbs;
 
@@ -5847,7 +5847,7 @@
         case MBEDTLS_ECP_DP_SECP192R1:
             if (ctype == (mbedtls_ecp_modulus_type) MBEDTLS_ECP_MOD_COORDINATE) {
 #if defined(MBEDTLS_ECP_NIST_OPTIM)
-                modp = &ecp_mod_p192;
+                modp = &mbedtls_ecp_mod_p192_raw;
 #endif
                 p = (mbedtls_mpi_uint *) secp192r1_p;
                 p_limbs = CHARS_TO_LIMBS(sizeof(secp192r1_p));
@@ -5862,7 +5862,7 @@
         case MBEDTLS_ECP_DP_SECP224R1:
             if (ctype == (mbedtls_ecp_modulus_type) MBEDTLS_ECP_MOD_COORDINATE) {
 #if defined(MBEDTLS_ECP_NIST_OPTIM)
-                modp = &ecp_mod_p224;
+                modp = &mbedtls_ecp_mod_p224_raw;
 #endif
                 p = (mbedtls_mpi_uint *) secp224r1_p;
                 p_limbs = CHARS_TO_LIMBS(sizeof(secp224r1_p));
@@ -5877,7 +5877,7 @@
         case MBEDTLS_ECP_DP_SECP256R1:
             if (ctype == (mbedtls_ecp_modulus_type) MBEDTLS_ECP_MOD_COORDINATE) {
 #if defined(MBEDTLS_ECP_NIST_OPTIM)
-                modp = &ecp_mod_p256;
+                modp = &mbedtls_ecp_mod_p256_raw;
 #endif
                 p = (mbedtls_mpi_uint *) secp256r1_p;
                 p_limbs = CHARS_TO_LIMBS(sizeof(secp256r1_p));
@@ -5892,7 +5892,7 @@
         case MBEDTLS_ECP_DP_SECP384R1:
             if (ctype == (mbedtls_ecp_modulus_type) MBEDTLS_ECP_MOD_COORDINATE) {
 #if defined(MBEDTLS_ECP_NIST_OPTIM)
-                modp = &ecp_mod_p384;
+                modp = &mbedtls_ecp_mod_p384_raw;
 #endif
                 p = (mbedtls_mpi_uint *) secp384r1_p;
                 p_limbs = CHARS_TO_LIMBS(sizeof(secp384r1_p));
@@ -5907,7 +5907,7 @@
         case MBEDTLS_ECP_DP_SECP521R1:
             if (ctype == (mbedtls_ecp_modulus_type) MBEDTLS_ECP_MOD_COORDINATE) {
 #if defined(MBEDTLS_ECP_NIST_OPTIM)
-                modp = &ecp_mod_p521;
+                modp = &mbedtls_ecp_mod_p521_raw;
 #endif
                 p = (mbedtls_mpi_uint *) secp521r1_p;
                 p_limbs = CHARS_TO_LIMBS(sizeof(secp521r1_p));
@@ -5957,7 +5957,7 @@
 #if defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED)
         case MBEDTLS_ECP_DP_CURVE25519:
             if (ctype == (mbedtls_ecp_modulus_type) MBEDTLS_ECP_MOD_COORDINATE) {
-                modp = &ecp_mod_p255;
+                modp = &mbedtls_ecp_mod_p255_raw;
                 p = (mbedtls_mpi_uint *) curve25519_p;
                 p_limbs = CHARS_TO_LIMBS(sizeof(curve25519_p));
             } else {
@@ -5970,7 +5970,7 @@
 #if defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED)
         case MBEDTLS_ECP_DP_SECP192K1:
             if (ctype == (mbedtls_ecp_modulus_type) MBEDTLS_ECP_MOD_COORDINATE) {
-                modp = &ecp_mod_p192;
+                modp = &mbedtls_ecp_mod_p192_raw;
                 p = (mbedtls_mpi_uint *) secp192k1_p;
                 p_limbs = CHARS_TO_LIMBS(sizeof(secp192k1_p));
             } else {
@@ -5983,7 +5983,7 @@
 #if defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
         case MBEDTLS_ECP_DP_SECP224K1:
             if (ctype == (mbedtls_ecp_modulus_type) MBEDTLS_ECP_MOD_COORDINATE) {
-                modp = &ecp_mod_p224;
+                modp = &mbedtls_ecp_mod_p224_raw;
                 p = (mbedtls_mpi_uint *) secp224k1_p;
                 p_limbs = CHARS_TO_LIMBS(sizeof(secp224k1_p));
             } else {
@@ -5996,7 +5996,7 @@
 #if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
         case MBEDTLS_ECP_DP_SECP256K1:
             if (ctype == (mbedtls_ecp_modulus_type) MBEDTLS_ECP_MOD_COORDINATE) {
-                modp = &ecp_mod_p256;
+                modp = &mbedtls_ecp_mod_p256_raw;
                 p = (mbedtls_mpi_uint *) secp256k1_p;
                 p_limbs = CHARS_TO_LIMBS(sizeof(secp256k1_p));
             } else {
@@ -6009,7 +6009,7 @@
 #if defined(MBEDTLS_ECP_DP_CURVE448_ENABLED)
         case MBEDTLS_ECP_DP_CURVE448:
             if (ctype == (mbedtls_ecp_modulus_type) MBEDTLS_ECP_MOD_COORDINATE) {
-                modp = &ecp_mod_p448;
+                modp = &mbedtls_ecp_mod_p448_raw;
                 p = (mbedtls_mpi_uint *) curve448_p;
                 p_limbs = CHARS_TO_LIMBS(sizeof(curve448_p));
             } else {