diff --git a/library/bignum_mod.c b/library/bignum_mod.c
index b277f5da3..9584ec29e 100644
--- a/library/bignum_mod.c
+++ b/library/bignum_mod.c
@@ -59,16 +59,16 @@ void mbedtls_mpi_mod_residue_release(mbedtls_mpi_mod_residue *r)
     r->p = NULL;
 }
 
-void mbedtls_mpi_mod_modulus_init(mbedtls_mpi_mod_modulus *m)
+void mbedtls_mpi_mod_modulus_init( mbedtls_mpi_mod_modulus *N )
 {
-    if (m == NULL) {
+    if (N == NULL) {
         return;
     }
 
-    m->p = NULL;
-    m->limbs = 0;
-    m->bits = 0;
-    m->int_rep = MBEDTLS_MPI_MOD_REP_INVALID;
+    N->p = NULL;
+    N->limbs = 0;
+    N->bits = 0;
+    N->int_rep = MBEDTLS_MPI_MOD_REP_INVALID;
 }
 
 void mbedtls_mpi_mod_modulus_free(mbedtls_mpi_mod_modulus *m)
diff --git a/library/bignum_mod.h b/library/bignum_mod.h
index 8e617b6a5..08f2e4a7b 100644
--- a/library/bignum_mod.h
+++ b/library/bignum_mod.h
@@ -185,20 +185,20 @@ void mbedtls_mpi_mod_residue_release(mbedtls_mpi_mod_residue *r);
 
 /** Initialize a modulus structure.
  *
- * \param[out] m     The address of the modulus structure to initialize.
+ * \param[out] N     The address of the modulus structure to initialize.
  */
-void mbedtls_mpi_mod_modulus_init(mbedtls_mpi_mod_modulus *m);
+void mbedtls_mpi_mod_modulus_init( mbedtls_mpi_mod_modulus *N );
 
 /** Setup a modulus structure.
  *
- * \param[out] m    The address of the modulus structure to populate.
- * \param[in] p     The address of the limb array storing the value of \p m.
- *                  The memory pointed to by \p p will be used by \p m and must
+ * \param[out] N    The address of the modulus structure to populate.
+ * \param[in] p     The address of the limb array storing the value of \p N.
+ *                  The memory pointed to by \p p will be used by \p N and must
  *                  not be modified in any way until after
  *                  mbedtls_mpi_mod_modulus_free() is called.
  * \param p_limbs   The number of limbs of \p p.
  * \param int_rep   The internal representation to be used for residues
- *                  associated with \p m (see #mbedtls_mpi_mod_rep_selector).
+ *                  associated with \p N (see #mbedtls_mpi_mod_rep_selector).
  *
  * \return      \c 0 if successful.
  * \return      #MBEDTLS_ERR_MPI_BAD_INPUT_DATA if \p int_rep is invalid.