diff --git a/library/bignum_mod_raw.c b/library/bignum_mod_raw.c
index 01f5a4423f..94dcf7724c 100644
--- a/library/bignum_mod_raw.c
+++ b/library/bignum_mod_raw.c
@@ -120,11 +120,11 @@ int mbedtls_mpi_mod_raw_write( const mbedtls_mpi_uint *A,
 
 /* BEGIN MERGE SLOT 5 */
 void mbedtls_mpi_mod_raw_add( mbedtls_mpi_uint *X,
-                              mbedtls_mpi_uint const *A,
-                              mbedtls_mpi_uint const *B,
+                              const mbedtls_mpi_uint *A,
+                              const mbedtls_mpi_uint *B,
                               const mbedtls_mpi_mod_modulus *N )
 {
-    size_t carry, borrow = 0;
+    mbedtls_mpi_uint carry, borrow;
     carry  = mbedtls_mpi_core_add( X, A, B, N->limbs );
     borrow = mbedtls_mpi_core_sub( X, X, N->p, N->limbs );
     (void) mbedtls_mpi_core_add_if( X, N->p, N->limbs, ( carry < borrow ) );
diff --git a/library/bignum_mod_raw.h b/library/bignum_mod_raw.h
index d6522381bb..bcb4a1596c 100644
--- a/library/bignum_mod_raw.h
+++ b/library/bignum_mod_raw.h
@@ -170,8 +170,8 @@ int mbedtls_mpi_mod_raw_write( const mbedtls_mpi_uint *A,
  * \param[in] N     The address of the modulus.
  */
 void mbedtls_mpi_mod_raw_add( mbedtls_mpi_uint *X,
-                              mbedtls_mpi_uint const *A,
-                              mbedtls_mpi_uint const *B,
+                              const mbedtls_mpi_uint *A,
+                              const mbedtls_mpi_uint *B,
                               const mbedtls_mpi_mod_modulus *N );
 /* END MERGE SLOT 5 */