diff --git a/README.md b/README.md
index 2ba21b85..d22736c9 100644
--- a/README.md
+++ b/README.md
@@ -20,7 +20,7 @@ Builds on Linux (x86_64 and aarch64), MacOS, OpenBSD, and Haiku. Builds for
 all of those host platforms plus mingw64, iOS, and android.
 
 1. Requires openssl (`libssl-dev`, in debian-speak). All other dependencies
-   are kept up to date in the tree.
+   are kept up to date in the tree, download them using `git submodule init` and `git submodule update`.
 2. To build, run `make debug` or `make release`. An executable will be
    generated in a subdirectory of `out/`.
 3. It's possible to build for Android, iOS, and Windows on Linux, if you have