diff --git a/pkgs/games/factorio/default.nix b/pkgs/games/factorio/default.nix
index 4b568a2aaf58..bd05c3728100 100644
--- a/pkgs/games/factorio/default.nix
+++ b/pkgs/games/factorio/default.nix
@@ -4,7 +4,7 @@
 , releaseType
 , mods ? []
 , username ? "", token ? "" # get/reset token at https://factorio.com/profile
-, experimental ? false
+, experimental ? false # true means to always use the latest branch
 }:
 
 assert releaseType == "alpha"
@@ -47,15 +47,17 @@ let
 
   branch = if experimental then "experimental" else "stable";
 
+  # NB `experimental` directs us to take the latest build, regardless of its branch;
+  # hence the (stable, experimental) pairs may sometimes refer to the same distributable.
   binDists = {
     x86_64-linux = let bdist = bdistForArch { inUrl = "linux64"; inTar = "x64"; }; in {
       alpha = {
         stable        = bdist { sha256 = "0b4hbpdcrh5hgip9q5dkmw22p66lcdhnr0kmb0w5dw6yi7fnxxh0"; version = "0.16.51"; withAuth = true; };
-        experimental  = bdist { sha256 = "1qwfivl5wf0ii8c4prdl4yili23qimsh2cj874r37q3ygpjk3bd3"; version = "0.16.50"; withAuth = true; };
+        experimental  = bdist { sha256 = "0b4hbpdcrh5hgip9q5dkmw22p66lcdhnr0kmb0w5dw6yi7fnxxh0"; version = "0.16.51"; withAuth = true; };
       };
       headless = {
         stable        = bdist { sha256 = "0zrnpg2js0ysvx9y50h3gajldk16mv02dvrwnkazh5kzr1d9zc3c"; version = "0.16.51"; };
-        experimental  = bdist { sha256 = "00691kr85p58qpxf3889p20nrgsvsyspx3c8yd11dkg46wly06z1"; version = "0.16.50"; };
+        experimental  = bdist { sha256 = "0zrnpg2js0ysvx9y50h3gajldk16mv02dvrwnkazh5kzr1d9zc3c"; version = "0.16.51"; };
       };
       demo = {
         stable        = bdist { sha256 = "0zf61z8937yd8pyrjrqdjgd0rjl7snwrm3xw86vv7s7p835san6a"; version = "0.16.51"; };