diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c
index c0bb3778f1ae..666f1962a160 100644
--- a/crypto/ansi_cprng.c
+++ b/crypto/ansi_cprng.c
@@ -230,11 +230,11 @@ static int get_prng_bytes(char *buf, size_t nbytes, struct prng_context *ctx,
 	 */
 	if (byte_count < DEFAULT_BLK_SZ) {
 empty_rbuf:
-		for (; ctx->rand_data_valid < DEFAULT_BLK_SZ;
-			ctx->rand_data_valid++) {
+		while (ctx->rand_data_valid < DEFAULT_BLK_SZ) {
 			*ptr = ctx->rand_data[ctx->rand_data_valid];
 			ptr++;
 			byte_count--;
+			ctx->rand_data_valid++;
 			if (byte_count == 0)
 				goto done;
 		}