diff --git a/README.md b/README.md
index b39a7b0..23d5cb3 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,11 @@ A web-browser viewer for anatomical flatmaps generated by [flatmap-maker](https:
 ### Installation
 
 1.  Clone this repository.
-2.  Run `bun install` in the checked out working directory.
+2.  Clone submodules in this repository with the following command:
+    ```
+    git submodule update --init --recursive
+    ```
+3.  Run `bun install` in the checked out working directory.
 
 
 ### Configuration