diff --git a/crates/voicevox_core_java_api/src/synthesizer.rs b/crates/voicevox_core_java_api/src/synthesizer.rs
index 9572c6ce6..32cdf1200 100644
--- a/crates/voicevox_core_java_api/src/synthesizer.rs
+++ b/crates/voicevox_core_java_api/src/synthesizer.rs
@@ -107,7 +107,7 @@ unsafe extern "system" fn Java_jp_hiroshiba_voicevoxcore_Synthesizer_rsLoadVoice
 ) {
     throw_if_err(env, (), |env| {
         let model = env
-            .get_rust_field::<_, _, Arc<crate::voice_model::VoiceModelFile>>(&model, "handle")?
+            .get_rust_field::<_, _, crate::voice_model::VoiceModelFile>(&model, "handle")?
             .clone();
         let model = model.read()?;
         let internal = env
diff --git a/crates/voicevox_core_java_api/src/voice_model.rs b/crates/voicevox_core_java_api/src/voice_model.rs
index 38dcc2371..ef24edbfe 100644
--- a/crates/voicevox_core_java_api/src/voice_model.rs
+++ b/crates/voicevox_core_java_api/src/voice_model.rs
@@ -7,7 +7,7 @@ use jni::{
     JNIEnv,
 };
 
-pub(crate) type VoiceModelFile = Closable<voicevox_core::blocking::VoiceModelFile>;
+pub(crate) type VoiceModelFile = Arc<Closable<voicevox_core::blocking::VoiceModelFile>>;
 
 impl HasJavaClassIdent for voicevox_core::blocking::VoiceModelFile {
     const JAVA_CLASS_IDENT: &str = "VoiceModelFile";
@@ -38,7 +38,7 @@ unsafe extern "system" fn Java_jp_hiroshiba_voicevoxcore_VoiceModelFile_rsGetId<
 ) -> jobject {
     throw_if_err(env, std::ptr::null_mut(), |env| {
         let internal = env
-            .get_rust_field::<_, _, Arc<VoiceModelFile>>(&this, "handle")?
+            .get_rust_field::<_, _, VoiceModelFile>(&this, "handle")?
             .clone();
         let internal = internal.read()?;
 
@@ -55,7 +55,7 @@ unsafe extern "system" fn Java_jp_hiroshiba_voicevoxcore_VoiceModelFile_rsGetMet
 ) -> jobject {
     throw_if_err(env, std::ptr::null_mut(), |env| {
         let internal = env
-            .get_rust_field::<_, _, Arc<VoiceModelFile>>(&this, "handle")?
+            .get_rust_field::<_, _, VoiceModelFile>(&this, "handle")?
             .clone();
         let internal = internal.read()?;
 
@@ -71,7 +71,7 @@ unsafe extern "system" fn Java_jp_hiroshiba_voicevoxcore_VoiceModelFile_rsClose<
     this: JObject<'local>,
 ) {
     throw_if_err(env, (), |env| {
-        env.take_rust_field::<_, _, Arc<VoiceModelFile>>(&this, "handle")?
+        env.take_rust_field::<_, _, VoiceModelFile>(&this, "handle")?
             .close();
         Ok(())
     })