diff --git a/pkgs/applications/science/math/mathematica/versions.nix b/pkgs/applications/science/math/mathematica/versions.nix
index 96e6805df8bc..34fd3294a5ae 100644
--- a/pkgs/applications/science/math/mathematica/versions.nix
+++ b/pkgs/applications/science/math/mathematica/versions.nix
@@ -1,5 +1,11 @@
 { lib, requireFile }:
 
+/*
+ * To calculate the hash of an installer, use a command like this:
+ *
+ *   nix --extra-experimental-features nix-command hash file <installer-file>
+ */
+
 let versions = [
   {
     version = "13.2.0";