diff --git a/jsonpull.c b/jsonpull.c
index 4147b4f..3c9a2c9 100644
--- a/jsonpull.c
+++ b/jsonpull.c
@@ -100,7 +100,7 @@ static inline int read_wrap(json_pull *j) {
 	return c;
 }
 
-#define SIZE_FOR(i) ((size_t)(((i) + 31) & ~31))
+#define SIZE_FOR(i, size) ((size_t)((((i) + 31) & ~31) * size))
 
 static json_object *fabricate_object(json_object *parent, json_type type) {
 	json_object *o = malloc(sizeof(struct json_object));
@@ -124,12 +124,12 @@ static json_object *add_object(json_pull *j, json_type type) {
 	if (c != NULL) {
 		if (c->type == JSON_ARRAY) {
 			if (c->expect == JSON_ITEM) {
-				if (SIZE_FOR(c->length + 1) != SIZE_FOR(c->length)) {
-					if (SIZE_FOR(c->length + 1) < SIZE_FOR(c->length)) {
+				if (SIZE_FOR(c->length + 1, sizeof(json_object *)) != SIZE_FOR(c->length, sizeof(json_object *))) {
+					if (SIZE_FOR(c->length + 1, sizeof(json_object *)) < SIZE_FOR(c->length, sizeof(json_object *))) {
 						fprintf(stderr, "Array size overflow\n");
 						exit(EXIT_FAILURE);
 					}
-					c->array = realloc(c->array, SIZE_FOR(c->length + 1) * sizeof(json_object *));
+					c->array = realloc(c->array, SIZE_FOR(c->length + 1, sizeof(json_object *)));
 					if (c->array == NULL) {
 						perror("Out of memory");
 						exit(EXIT_FAILURE);
@@ -154,13 +154,13 @@ static json_object *add_object(json_pull *j, json_type type) {
 					return NULL;
 				}
 
-				if (SIZE_FOR(c->length + 1) != SIZE_FOR(c->length)) {
-					if (SIZE_FOR(c->length + 1) < SIZE_FOR(c->length)) {
+				if (SIZE_FOR(c->length + 1, sizeof(json_object *)) != SIZE_FOR(c->length, sizeof(json_object *))) {
+					if (SIZE_FOR(c->length + 1, sizeof(json_object *)) < SIZE_FOR(c->length, sizeof(json_object *))) {
 						fprintf(stderr, "Hash size overflow\n");
 						exit(EXIT_FAILURE);
 					}
-					c->keys = realloc(c->keys, SIZE_FOR(c->length + 1) * sizeof(json_object *));
-					c->values = realloc(c->values, SIZE_FOR(c->length + 1) * sizeof(json_object *));
+					c->keys = realloc(c->keys, SIZE_FOR(c->length + 1, sizeof(json_object *)));
+					c->values = realloc(c->values, SIZE_FOR(c->length + 1, sizeof(json_object *)));
 					if (c->keys == NULL || c->values == NULL) {
 						perror("Out of memory");
 						exit(EXIT_FAILURE);