diff --git a/packaging/dependencies.nix b/packaging/dependencies.nix
index 0af670bfb..ed05843c7 100644
--- a/packaging/dependencies.nix
+++ b/packaging/dependencies.nix
@@ -26,6 +26,9 @@ let
   # Despite the use of the 10.13 deployment target here, the aligned
   # allocation function Clang uses with this setting actually works
   # all the way back to 10.6.
+  # NOTE: this is not just a version constraint, but a request to make Darwin
+  #       provide this version level of support. Removing this minimum version
+  #       request will regress the above error.
   darwinStdenv = pkgs.overrideSDK prevStdenv { darwinMinVersion = "10.13"; };
 
 in