diff --git a/pkgs/development/ocaml-modules/extlib/1.7.7.nix b/pkgs/development/ocaml-modules/extlib/1.7.7.nix
index 0e4f326e177c..643e05972142 100644
--- a/pkgs/development/ocaml-modules/extlib/1.7.7.nix
+++ b/pkgs/development/ocaml-modules/extlib/1.7.7.nix
@@ -1,3 +1,4 @@
+# nixpkgs-update: no auto update
 # Older version of extlib for Haxe 4.0 and 4.1.
 # May be replaceable by the next extlib + extlib-base64 release.
 {
diff --git a/pkgs/development/ocaml-modules/luv/default.nix b/pkgs/development/ocaml-modules/luv/default.nix
index d055fa210892..207d1a1aea3e 100644
--- a/pkgs/development/ocaml-modules/luv/default.nix
+++ b/pkgs/development/ocaml-modules/luv/default.nix
@@ -1,3 +1,5 @@
+# nixpkgs-update: no auto update
+# haxe depends on specific version of luv
 {
   lib,
   buildDunePackage,