diff --git a/src/build_context.rs b/src/build_context.rs
index a14b5a1bb..91921a15a 100644
--- a/src/build_context.rs
+++ b/src/build_context.rs
@@ -68,6 +68,7 @@ pub enum ProjectLayout {
 impl ProjectLayout {
     /// Checks whether a python module exists besides Cargo.toml with the right name
     pub fn determine(project_root: impl AsRef<Path>, module_name: &str) -> Result<ProjectLayout> {
+        // A dot in the module name means the extension module goes into the module folder specified by the path
         let parts: Vec<&str> = module_name.split('.').collect();
         let (python_module, rust_module, extension_name) = if parts.len() > 1 {
             let mut rust_module = project_root.as_ref().to_path_buf();