diff --git a/src/generator.rs b/src/generator.rs
index 67c12c7..7a530a5 100644
--- a/src/generator.rs
+++ b/src/generator.rs
@@ -28,8 +28,8 @@ use thiserror::Error;
 pub enum CodeGenError {
     #[error("tokenization(syn) error: {0}")]
     SynError(#[from] syn::Error),
-    #[error("failed to create file: {0}")]
-    FilePathError(String),
+    #[error("failed to create file (name duplicated): {0}")]
+    FilePathDuplicatedError(String),
     #[error("parent is required for {module}")]
     ParentMissing { module: &'static str },
     #[error("Unsupported structure: {}", name)]
@@ -373,7 +373,7 @@ impl CodeGen for Block {
             log::error!("path {}", out_path.display());
             log::error!("old {}", old_out.to_string());
             log::error!("new {}", out.to_string());
-            return Err(CodeGenError::FilePathError(snake_case_name.to_string()));
+            return Err(CodeGenError::FilePathDuplicatedError(snake_case_name.to_string()));
         };
 
         let files = self.elements.into_iter().try_fold(files, |files, e| {
@@ -465,7 +465,7 @@ impl CodeGen for Register {
         let (out_path, _next_parent_path) = mod_file_path(parent_path, &snake_case_name);
         log::info!("{:?}", out_path);
         if files.insert(out_path, out).is_some() {
-            return Err(CodeGenError::FilePathError(snake_case_name.to_string()));
+            return Err(CodeGenError::FilePathDuplicatedError(snake_case_name.to_string()));
         }
         Ok(files)
     }