diff --git a/.gitignore b/.gitignore
index 0df78e1..7c1ec01 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,7 +4,7 @@ target/
 node_modules/
 package-lock.json
 package.json
-*.expanded.rs
+*_expanded.rs
 
 # Related to [Why do binaries have Cargo.lock in version control, but not libraries?](https://doc.rust-lang.org/cargo/faq.html#why-do-binaries-have-cargolock-in-version-control-but-not-libraries)
 Cargo.lock
diff --git a/justfile b/justfile
index f083abf..900c65a 100644
--- a/justfile
+++ b/justfile
@@ -77,6 +77,9 @@ bench:
     CRITERION_DEBUG=1 cargo bench; \
     start ./target/criterion/report/index.html
 
-expand test_file_name:
+expand test_file_name="util":
     rm -f {{test_file_name}}.expanded.rs; \
-    cargo expand --test {{test_file_name}} | save --raw {{test_file_name}}.expanded.rs
\ No newline at end of file
+    cargo expand --test {{test_file_name}} | save -f --raw src/{{test_file_name}}_expanded.rs
+
+expand_clean:
+    rm -f src/*_expanded.rs
\ No newline at end of file