diff --git a/thread_pthread.h b/thread_pthread.h
index f2b7e598f7..c5244fa32f 100644
--- a/thread_pthread.h
+++ b/thread_pthread.h
@@ -40,6 +40,8 @@ typedef struct native_thread_data_struct {
     } cond;
 } native_thread_data_t;
 
+void rb_native_mutex_destroy(rb_nativethread_lock_t *lock);
+
 #undef except
 #undef try
 #undef leave
diff --git a/thread_win32.h b/thread_win32.h
index 60083da0a1..1a46929ddc 100644
--- a/thread_win32.h
+++ b/thread_win32.h
@@ -32,5 +32,7 @@ typedef struct rb_global_vm_lock_struct {
     HANDLE lock;
 } rb_global_vm_lock_t;
 
+void rb_native_mutex_destroy(rb_nativethread_lock_t *lock);
+
 #endif /* RUBY_THREAD_WIN32_H */
 
diff --git a/version.h b/version.h
index 4c36f475c7..e787ee6a63 100644
--- a/version.h
+++ b/version.h
@@ -2,7 +2,7 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 3
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 178
+#define RUBY_PATCHLEVEL 179
 
 #define RUBY_RELEASE_YEAR 2021
 #define RUBY_RELEASE_MONTH 3