diff --git a/rust-toolchain b/rust-toolchain
new file mode 100644
index 000000000..50aceaa7b
--- /dev/null
+++ b/rust-toolchain
@@ -0,0 +1 @@
+1.45.0
diff --git a/shell.nix b/shell.nix
index bbda153f2..23da20cd3 100644
--- a/shell.nix
+++ b/shell.nix
@@ -9,9 +9,10 @@ pkgs.mkShell {
     git
     mypy
     neovim
-    cargo
-    rust-analyzer
+    rustup
+    rust-analyzer # For integration tests.
     tmux
+    vim # For manual tests.
     vim-vint
     (with python37Packages; [
       flake8