diff --git a/driver-avalon.c b/driver-avalon.c
index 3d670765..dd762b86 100644
--- a/driver-avalon.c
+++ b/driver-avalon.c
@@ -670,7 +670,8 @@ static bool avalon_prepare(struct thr_info *thr)
 	struct timeval now;
 
 	free(avalon->works);
-	avalon->works = calloc(info->miner_count * sizeof(struct work *), 4);
+	avalon->works = calloc(info->miner_count * sizeof(struct work *),
+			       AVALON_ARRAY_SIZE);
 	if (!avalon->works)
 		quit(1, "Failed to calloc avalon works in avalon_prepare");
 	if (avalon->device_fd == -1)
@@ -797,7 +798,7 @@ static bool avalon_fill(struct cgpu_info *avalon)
 static void avalon_rotate_array(struct cgpu_info *avalon)
 {
 	avalon->queued = 0;
-	if (++avalon->work_array > 3)
+	if (++avalon->work_array >= AVALON_ARRAY_SIZE)
 		avalon->work_array = 0;
 }
 
diff --git a/driver-avalon.h b/driver-avalon.h
index 93c2e60c..cdbd0d28 100644
--- a/driver-avalon.h
+++ b/driver-avalon.h
@@ -99,6 +99,7 @@ struct avalon_info {
 
 #define AVALON_WRITE_SIZE (sizeof(struct avalon_task))
 #define AVALON_READ_SIZE (sizeof(struct avalon_result))
+#define AVALON_ARRAY_SIZE 4
 
 #define AVA_GETS_ERROR -1
 #define AVA_GETS_OK 0