diff --git a/drivers/net/wireless/airo.c b/drivers/net/wireless/airo.c
index 44a2270..4ad910b 100644
--- a/drivers/net/wireless/airo.c
+++ b/drivers/net/wireless/airo.c
@@ -1623,7 +1623,7 @@
 
 	crypto_cipher_setkey(tfm, pkey, 16);
 	counter = 0;
-	for (i = 0; i < (sizeof(context->coeff)/sizeof(context->coeff[0])); ) {
+	for (i = 0; i < ARRAY_SIZE(context->coeff); ) {
 		aes_counter[15] = (u8)(counter >> 0);
 		aes_counter[14] = (u8)(counter >> 8);
 		aes_counter[13] = (u8)(counter >> 16);
@@ -1632,7 +1632,7 @@
 		memcpy (plain, aes_counter, 16);
 		crypto_cipher_encrypt_one(tfm, plain, plain);
 		cipher = plain;
-		for (j=0; (j<16) && (i< (sizeof(context->coeff)/sizeof(context->coeff[0]))); ) {
+		for (j = 0; (j < 16) && (i < ARRAY_SIZE(context->coeff)); ) {
 			context->coeff[i++] = ntohl(*(u32 *)&cipher[j]);
 			j += 4;
 		}