diff --git a/include/tinycrypt/ecc.h b/include/tinycrypt/ecc.h
index 3d60267cc..e016c696b 100644
--- a/include/tinycrypt/ecc.h
+++ b/include/tinycrypt/ecc.h
@@ -386,7 +386,7 @@ uECC_word_t uECC_vli_testBit(const uECC_word_t *vli, bitcount_t bit);
  * @warning Currently only designed to work for curve_p or curve_n.
  */
 void uECC_vli_mmod(uECC_word_t *result, uECC_word_t *product,
-		   const uECC_word_t *mod, wordcount_t num_words);
+		   const uECC_word_t *mod);
 
 /*
  * @brief Computes modular product (using curve->mmod_fast)
diff --git a/tinycrypt/ecc.c b/tinycrypt/ecc.c
index e7558e9a0..508831cb2 100644
--- a/tinycrypt/ecc.c
+++ b/tinycrypt/ecc.c
@@ -444,12 +444,13 @@ void uECC_vli_modSub(uECC_word_t *result, const uECC_word_t *left,
 /* Computes result = product % mod, where product is 2N words long. */
 /* Currently only designed to work for curve_p or curve_n. */
 void uECC_vli_mmod(uECC_word_t *result, uECC_word_t *product,
-    		   const uECC_word_t *mod, wordcount_t num_words)
+    		   const uECC_word_t *mod)
 {
 	uECC_word_t mod_multiple[2 * NUM_ECC_WORDS];
 	uECC_word_t tmp[2 * NUM_ECC_WORDS];
 	uECC_word_t *v[2] = {tmp, product};
 	uECC_word_t index;
+	const wordcount_t num_words = NUM_ECC_WORDS;
 
 	/* Shift mod so its highest set bit is at the maximum position. */
 	bitcount_t shift = (num_words * 2 * uECC_WORD_BITS) -
@@ -493,7 +494,8 @@ void uECC_vli_modMult(uECC_word_t *result, const uECC_word_t *left,
 {
 	uECC_word_t product[2 * NUM_ECC_WORDS];
 	uECC_vli_mult_rnd(product, left, right, NULL);
-	uECC_vli_mmod(result, product, mod, num_words);
+	uECC_vli_mmod(result, product, mod);
+	(void) num_words;
 }
 
 static void uECC_vli_modMult_rnd(uECC_word_t *result, const uECC_word_t *left,
diff --git a/tinycrypt/ecc_dh.c b/tinycrypt/ecc_dh.c
index 52208ad9d..71c51f5a8 100644
--- a/tinycrypt/ecc_dh.c
+++ b/tinycrypt/ecc_dh.c
@@ -123,7 +123,7 @@ int uECC_make_key(uint8_t *public_key, uint8_t *private_key, uECC_Curve curve)
 		}
 
 		/* computing modular reduction of _random (see FIPS 186.4 B.4.1): */
-		uECC_vli_mmod(_private, _random, curve->n, BITS_TO_WORDS(curve->num_n_bits));
+		uECC_vli_mmod(_private, _random, curve->n);
 
 		/* Computing public-key from private: */
 		if (EccPoint_compute_public_key(_public, _private, curve)) {
diff --git a/tinycrypt/ecc_dsa.c b/tinycrypt/ecc_dsa.c
index 77e3efee7..ca07eb191 100644
--- a/tinycrypt/ecc_dsa.c
+++ b/tinycrypt/ecc_dsa.c
@@ -182,7 +182,7 @@ int uECC_sign(const uint8_t *private_key, const uint8_t *message_hash,
 		}
 
 		// computing k as modular reduction of _random (see FIPS 186.4 B.5.1):
-		uECC_vli_mmod(k, _random, curve->n, BITS_TO_WORDS(curve->num_n_bits));
+		uECC_vli_mmod(k, _random, curve->n);
 
 		if (uECC_sign_with_k(private_key, message_hash, hash_size, k, signature, 
 		    curve)) {