diff --git a/README.md b/README.md
index a4df638..627227f 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,10 @@ For all those times when you need to create a recursively nested tree
 of `enum`s and find yourself in pain having to put everything in
 `Box`es all the time.
 
+## Differences to the upstream repo
+- Fixed an alignment issue as described [here](https://github.com/ratel-rust/toolshed/issues/11#issuecomment-1573659455). We're not confident in this fix but it's the best thing we have for now.
+- Rust version is locked to 1.73.0 as this is the last version that compiles (1.74 does not compile Toolshed anymore).
+
 ## Features
 
 + Paginated `Arena`: internally preallocates 64KiB _pages_ on the heap and
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
new file mode 100644
index 0000000..60e6cbb
--- /dev/null
+++ b/rust-toolchain.toml
@@ -0,0 +1,4 @@
+[toolchain]
+channel = "1.73.0"
+components = []
+profile = "minimal"