diff --git a/.lintstagedrc.js b/.lintstagedrc.js
--- a/.lintstagedrc.js
+++ b/.lintstagedrc.js
@@ -1,5 +1,6 @@
 const { CLIEngine } = require('eslint');
 const { getClangPaths } = require('./scripts/get_clang_paths');
+const { findRustProjectPath } = require('./scripts/get_cargo_path');
 
 const cli = new CLIEngine({});
 
@@ -58,8 +59,9 @@
     });
     return 'clang-format -i ' + files.join(' ');
   },
-  'services/commtest/**/*.rs': function rustFormat(files) {
-    return 'yarn rust-pre-commit';
+  '*.rs': function rustFormat(files) {
+    const paths = new Set(files.map(findRustProjectPath).filter(Boolean));
+    return `yarn rust-pre-commit ${Array.from(paths).join(' ')}`;
   },
   'services/terraform/*.tf': function checkTerraform(files) {
     return 'yarn terraform-pre-commit';
diff --git a/scripts/get_cargo_path.js b/scripts/get_cargo_path.js
new file mode 100644
--- /dev/null
+++ b/scripts/get_cargo_path.js
@@ -0,0 +1,12 @@
+// @flow
+
+const findUp = require('find-up');
+
+// finds the path to the parent directory containing a Cargo.toml file for the
+// given path. Returns null if no Cargo.toml file is found.
+function findRustProjectPath(path) {
+  const cargoTomlPath = findUp.sync('Cargo.toml', { cwd: path });
+  return cargoTomlPath ? cargoTomlPath.replace('/Cargo.toml', '') : null;
+}
+
+module.exports = { findRustProjectPath };
diff --git a/scripts/rust_pre_commit.sh b/scripts/rust_pre_commit.sh
--- a/scripts/rust_pre_commit.sh
+++ b/scripts/rust_pre_commit.sh
@@ -5,17 +5,21 @@
 # shellcheck source=/dev/null
 [[ -r "$HOME"/.cargo/env ]] && source "$HOME"/.cargo/env
 
-PATHS="services/commtest"
+if [[ "$#" -eq 0 ]]; then
+  echo "no Cargo project paths provided"
+  exit 1
+fi
 
 command -v cargo > /dev/null
 
-for directory in $PATHS; do
-  pushd "$directory"
+# iterate over all provided Cargo project paths
+for directory in "$@"; do
+  pushd "$directory" > /dev/null
   echo "formatting ${directory}..."
   cargo fmt --all -- --check
   echo "checking ${directory}..."
   cargo check
-  popd # $directory
+  popd > /dev/null # $directory
 done
 
 echo "done formatting"