diff --git a/crates/voicevox_core_c_api/src/lib.rs b/crates/voicevox_core_c_api/src/lib.rs
index 36a40c547..2b1e4f51b 100644
--- a/crates/voicevox_core_c_api/src/lib.rs
+++ b/crates/voicevox_core_c_api/src/lib.rs
@@ -52,7 +52,7 @@ pub struct VoicevoxInitializeOptions {
 }
 
 #[no_mangle]
-pub extern "C" fn voicevox_default_initialize_options() -> VoicevoxInitializeOptions {
+pub extern "C" fn voicevox_make_default_initialize_options() -> VoicevoxInitializeOptions {
     VoicevoxInitializeOptions::default()
 }
 
@@ -184,7 +184,7 @@ pub struct VoicevoxAudioQueryOptions {
 }
 
 #[no_mangle]
-pub extern "C" fn voicevox_default_audio_query_options() -> VoicevoxAudioQueryOptions {
+pub extern "C" fn voicevox_make_default_audio_query_options() -> VoicevoxAudioQueryOptions {
     voicevox_core::AudioQueryOptions::default().into()
 }
 
@@ -213,7 +213,7 @@ pub struct VoicevoxSynthesisOptions {
     enable_interrogative_upspeak: bool,
 }
 
-pub extern "C" fn voicevox_default_synthesis_options() -> VoicevoxSynthesisOptions {
+pub extern "C" fn voicevox_make_default_synthesis_options() -> VoicevoxSynthesisOptions {
     VoicevoxSynthesisOptions::default()
 }
 
@@ -258,7 +258,7 @@ pub struct VoicevoxTtsOptions {
 }
 
 #[no_mangle]
-pub extern "C" fn voicevox_default_tts_options() -> VoicevoxTtsOptions {
+pub extern "C" fn voicevox_make_default_tts_options() -> VoicevoxTtsOptions {
     voicevox_core::TtsOptions::default().into()
 }
 
diff --git a/example/cpp/unix/simple_tts.cpp b/example/cpp/unix/simple_tts.cpp
index fd08fd426..3feebd461 100644
--- a/example/cpp/unix/simple_tts.cpp
+++ b/example/cpp/unix/simple_tts.cpp
@@ -17,7 +17,7 @@ int main(int argc, char *argv[]) {
 
   std::cout << "coreの初期化中..." << std::endl;
 
-  auto initialize_options = voicevox_default_initialize_options();
+  auto initialize_options = voicevox_make_default_initialize_options();
   initialize_options.load_all_models = true;
   initialize_options.open_jtalk_dict_dir = open_jtalk_dict_path.c_str();
   if (voicevox_initialize(initialize_options) != VOICEVOX_RESULT_SUCCEED) {