diff --git a/packages/backend-rs/src/util/check_word_mute.rs b/packages/backend-rs/src/util/check_word_mute.rs
index 085383fc..865dc18c 100644
--- a/packages/backend-rs/src/util/check_word_mute.rs
+++ b/packages/backend-rs/src/util/check_word_mute.rs
@@ -1,10 +1,10 @@
 use crate::database::JsDbConn;
 use crate::model::entity::{drive_file, note};
+use crate::prelude::*;
 use once_cell::sync::Lazy;
 use regex::Regex;
 use sea_orm::prelude::*;
 
-// FIXME: remove this type
 #[napi_derive::napi(object)]
 pub struct NoteLike {
     pub file_ids: Vec<String>,
@@ -15,82 +15,76 @@ pub struct NoteLike {
     pub reply_id: Option<String>,
 }
 
-async fn full_text(conn: &JsDbConn, note: NoteLike) -> String {
-    let mut to_return = format!(
-        "{}\n{}\n",
-        note.text.unwrap_or_default(),
-        note.cw.unwrap_or_default(),
-    );
+async fn all_texts(conn: &JsDbConn, note: NoteLike) -> napi::Result<Vec<String>> {
+    let mut texts: Vec<String> = vec![];
+
+    if let Some(text) = note.text {
+        texts.push(text);
+    }
+    if let Some(cw) = note.cw {
+        texts.push(cw);
+    }
 
     for file_id in note.file_ids {
         if let Some(alt_text) = drive_file::Entity::find_by_id(file_id)
             .one(conn.inner())
             .await
-            .expect("Failed to connect to the database")
-            .expect("file_id is invalid")
+            .map_err(to_napi_error)?
+            .ok_or_else(|| to_napi_error("file_id is invalid"))?
             .comment
         {
-            to_return.push_str(alt_text.as_str());
-            to_return.push('\n');
+            texts.push(alt_text);
         }
     }
 
-    if note.renote_id.is_some() {
-        to_return.push_str(
-            note::Entity::find_by_id(note.renote_id.unwrap())
-                .one(conn.inner())
-                .await
-                .expect("Failed to connect to the database")
-                .expect("renote_id is invalid")
-                .text
-                .unwrap_or_default()
-                .as_str(),
-        );
-        to_return.push('\n');
+    if let Some(renote_id) = note.renote_id {
+        if let Some(text) = note::Entity::find_by_id(renote_id)
+            .one(conn.inner())
+            .await
+            .map_err(to_napi_error)?
+            .ok_or_else(|| to_napi_error("renote_id is invalid"))?
+            .text
+        {
+            texts.push(text);
+        }
     }
 
-    if note.reply_id.is_some() {
-        to_return.push_str(
-            note::Entity::find_by_id(note.reply_id.unwrap())
-                .one(conn.inner())
-                .await
-                .expect("Failed to connect to the database")
-                .expect("reply_id is invalid")
-                .text
-                .unwrap_or_default()
-                .as_str(),
-        );
+    if let Some(reply_id) = note.reply_id {
+        if let Some(text) = note::Entity::find_by_id(reply_id)
+            .one(conn.inner())
+            .await
+            .map_err(to_napi_error)?
+            .ok_or_else(|| to_napi_error("reply_id is invalid"))?
+            .text
+        {
+            texts.push(text);
+        }
     }
 
-    to_return.trim().to_owned()
+    Ok(texts)
 }
 
-// FIXME: remove this funtion
-fn convert_regex(js_regex: String) -> String {
+fn convert_regex(js_regex: &str) -> String {
     static RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"^/(.+)/(.*)$").unwrap());
-    RE.replace(&js_regex, "(?$2)$1").to_string()
+    RE.replace(js_regex, "(?$2)$1").to_string()
 }
 
-async fn check_word_mute_impl(
-    text: String,
-    muted_word_lists: Vec<Vec<String>>,
-    muted_patterns: Vec<String>,
+fn check_word_mute_impl(
+    texts: &[String],
+    muted_word_lists: &[Vec<String>],
+    muted_patterns: &[String],
 ) -> bool {
-    if text.is_empty() {
-        return false;
-    }
-
-    let text_lowercase = text.to_lowercase();
-
-    muted_word_lists.into_iter().any(|muted_word_list| {
-        muted_word_list
-            .into_iter()
-            .all(|muted_word| text_lowercase.contains(&muted_word.to_lowercase()))
-    }) || muted_patterns.into_iter().any(|muted_patten| {
-        match Regex::new(convert_regex(muted_patten).as_str()) {
-            Ok(re) => re.is_match(&text),
-            Err(_) => false,
-        }
+    muted_word_lists.iter().any(|muted_word_list| {
+        texts.iter().any(|text| {
+            let text_lower = text.to_lowercase();
+            muted_word_list
+                .iter()
+                .all(|muted_word| text_lower.contains(muted_word))
+        })
+    }) || muted_patterns.iter().any(|muted_pattern| {
+        Regex::new(convert_regex(muted_pattern).as_str())
+            .map(|re| texts.iter().any(|text| re.is_match(text)))
+            .unwrap_or(false)
     })
 }
 
@@ -100,15 +94,14 @@ pub async fn check_word_mute(
     note: NoteLike,
     muted_word_lists: Vec<Vec<String>>,
     muted_patterns: Vec<String>,
-) -> bool {
+) -> napi::Result<bool> {
     if muted_word_lists.is_empty() && muted_patterns.is_empty() {
-        false
+        Ok(false)
     } else {
-        check_word_mute_impl(
-            full_text(conn, note).await,
-            muted_word_lists,
-            muted_patterns,
-        )
-        .await
+        Ok(check_word_mute_impl(
+            &all_texts(conn, note).await?,
+            &muted_word_lists,
+            &muted_patterns,
+        ))
     }
 }