diff --git a/proposals/4120-head-method-download.md b/proposals/4120-head-method-download.md
index b9edb3cf..5af36d30 100644
--- a/proposals/4120-head-method-download.md
+++ b/proposals/4120-head-method-download.md
@@ -68,4 +68,4 @@ generated by that Synapse instance.
 
 ## Dependencies
 
-This proposal does not have any direct dependencies.
+This proposal doesn't work very well without [MSC4138](https://github.com/matrix-org/matrix-spec-proposals/pull/4138).