diff --git a/libvips/foreign/gifnsload.c b/libvips/foreign/gifnsload.c
index 8ed5bf8f..8e4cc358 100644
--- a/libvips/foreign/gifnsload.c
+++ b/libvips/foreign/gifnsload.c
@@ -56,6 +56,10 @@
  *
  * - libnsgif does not seem to support comment metadata
  *
+ * - dispose_previous is not handled correctly by libnsgif
+ *
+ * - it always loads the entire source file into memory
+ *
  * Notes:
  *
  * - hard to detect mono images -- local_colour_table in libnsgif is only set