diff --git a/Developer-guides.md b/Developer-guides.md
index f8a0fdd..9050af8 100644
--- a/Developer-guides.md
+++ b/Developer-guides.md
@@ -113,6 +113,12 @@ Warning: Saved sessions may no longer be usable when the number of contexts is s
 
 Discard filter key when there's no match.
 
+#### Disable sorting on directory load
+
+    make O_NOSORT=1
+
+This option is useful in _type-to-nav_ mode. Loads dirs faster on initial entry. Any filter sorts the listing.
+
 ## Static compilation
 
 Install the GPM development library and set the Makefile variable `O_STATIC`.