diff --git a/.ls-lint.yml b/.ls-lint.yml
index 31a1ef2..5e8c7f9 100644
--- a/.ls-lint.yml
+++ b/.ls-lint.yml
@@ -1,9 +1,15 @@
 ls:
   .dir: regex:\.?[a-z0-9]+(-[a-z0-9]+)*
-  .md: regex:[a-z0-9]*([._][a-z0-9]+)* | regex:(README|CONTRIBUTING|CHANGELOG|AGENTS|CLAUDE|SKILL)
-  .toml: regex:[a-z0-9]*([._][a-z0-9]+)* | regex:Cargo
-  .lock: regex:[a-z0-9]*([._][a-z0-9]+)* | regex:Cargo
-  .*: regex:[a-z0-9]*([._][a-z0-9]+)*
+  <<: &files
+    .md: regex:[a-z0-9]*([._][a-z0-9]+)* | regex:(README|CONTRIBUTING|CHANGELOG|AGENTS|CLAUDE|SKILL)
+    .toml: regex:[a-z0-9]*([._][a-z0-9]+)* | regex:Cargo
+    .lock: regex:[a-z0-9]*([._][a-z0-9]+)* | regex:Cargo
+    .*: regex:[a-z0-9]*([._][a-z0-9]+)*
+  # Rust module directories are identifiers, so they use snake_case.
+  # A nested block replaces the root rules, so it re-merges the file rules.
+  src:
+    <<: *files
+    .dir: regex:[a-z0-9]+(_[a-z0-9]+)*
 
 ignore:
   - .git