diff --git a/src/picture.c b/src/picture.c
index b3d5eb0..10c93a7 100644
--- a/src/picture.c
+++ b/src/picture.c
@@ -75,7 +75,7 @@ void picture_append_data(struct picture_t *picture, const unsigned char *data, s
 void picture_copy(const struct picture_t *src, struct picture_t *dest) {
 	assert(src->allocated);
 
-	picture_set_data(dest, src->data, src->allocated);
+	picture_set_data(dest, src->data, src->used);
 
 #	define COPY(_field) dest->_field = src->_field