diff --git a/tinycrypt/ecc_dsa.c b/tinycrypt/ecc_dsa.c
index a3b91b8..f4af4b6 100644
--- a/tinycrypt/ecc_dsa.c
+++ b/tinycrypt/ecc_dsa.c
@@ -219,7 +219,7 @@
 
 	uECC_word_t _public[NUM_ECC_WORDS * 2];
 	uECC_word_t r[NUM_ECC_WORDS], s[NUM_ECC_WORDS];
-	wordcount_t num_words = curve->num_words;
+	wordcount_t num_words = NUM_ECC_WORDS;
 	wordcount_t num_n_words = BITS_TO_WORDS(curve->num_n_bits);
 
 	if (curve != uECC_secp256r1())