diff --git a/crates/voicevox_core_c_api/src/lib.rs b/crates/voicevox_core_c_api/src/lib.rs
index abe83ca3a..d4ea8d7a3 100644
--- a/crates/voicevox_core_c_api/src/lib.rs
+++ b/crates/voicevox_core_c_api/src/lib.rs
@@ -1061,7 +1061,7 @@ pub unsafe extern "C" fn voicevox_user_dict_add_word(
     output_word_uuid: NonNull<[u8; 16]>,
 ) -> VoicevoxResultCode {
     into_result_code_with_error((|| {
-        let word = (*word).try_into_word()?;
+        let word = word.read_unaligned().try_into_word()?;
         let uuid = {
             let mut dict = user_dict.dict.lock().expect("lock failed");
             dict.add_word(word)?
@@ -1092,7 +1092,7 @@ pub unsafe extern "C" fn voicevox_user_dict_update_word(
 ) -> VoicevoxResultCode {
     into_result_code_with_error((|| {
         let word_uuid = Uuid::from_slice(word_uuid).map_err(CApiError::InvalidUuid)?;
-        let word = (*word).try_into_word()?;
+        let word = word.read_unaligned().try_into_word()?;
         {
             let mut dict = user_dict.dict.lock().expect("lock failed");
             dict.update_word(word_uuid, word)?;