diff --git a/common.mk b/common.mk
index 46d18063a3..7e585d3fff 100644
--- a/common.mk
+++ b/common.mk
@@ -3372,7 +3372,7 @@ cont.$(OBJEXT): {$(VPATH)}missing.h
 cont.$(OBJEXT): {$(VPATH)}mjit.h
 cont.$(OBJEXT): {$(VPATH)}node.h
 cont.$(OBJEXT): {$(VPATH)}ractor.h
-cont.$(OBJEXT): {$(VPATH)}ractor_pub.h
+cont.$(OBJEXT): {$(VPATH)}ractor_core.h
 cont.$(OBJEXT): {$(VPATH)}ruby_assert.h
 cont.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 cont.$(OBJEXT): {$(VPATH)}st.h
@@ -3566,7 +3566,7 @@ debug.$(OBJEXT): {$(VPATH)}node.h
 debug.$(OBJEXT): {$(VPATH)}onigmo.h
 debug.$(OBJEXT): {$(VPATH)}oniguruma.h
 debug.$(OBJEXT): {$(VPATH)}ractor.h
-debug.$(OBJEXT): {$(VPATH)}ractor_pub.h
+debug.$(OBJEXT): {$(VPATH)}ractor_core.h
 debug.$(OBJEXT): {$(VPATH)}ruby_assert.h
 debug.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 debug.$(OBJEXT): {$(VPATH)}st.h
@@ -4622,7 +4622,6 @@ encoding.$(OBJEXT): {$(VPATH)}missing.h
 encoding.$(OBJEXT): {$(VPATH)}node.h
 encoding.$(OBJEXT): {$(VPATH)}onigmo.h
 encoding.$(OBJEXT): {$(VPATH)}oniguruma.h
-encoding.$(OBJEXT): {$(VPATH)}ractor_pub.h
 encoding.$(OBJEXT): {$(VPATH)}regenc.h
 encoding.$(OBJEXT): {$(VPATH)}ruby_assert.h
 encoding.$(OBJEXT): {$(VPATH)}st.h
@@ -5402,7 +5401,7 @@ eval.$(OBJEXT): {$(VPATH)}probes.dmyh
 eval.$(OBJEXT): {$(VPATH)}probes.h
 eval.$(OBJEXT): {$(VPATH)}probes_helper.h
 eval.$(OBJEXT): {$(VPATH)}ractor.h
-eval.$(OBJEXT): {$(VPATH)}ractor_pub.h
+eval.$(OBJEXT): {$(VPATH)}ractor_core.h
 eval.$(OBJEXT): {$(VPATH)}ruby_assert.h
 eval.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 eval.$(OBJEXT): {$(VPATH)}st.h
@@ -5824,7 +5823,7 @@ gc.$(OBJEXT): {$(VPATH)}oniguruma.h
 gc.$(OBJEXT): {$(VPATH)}probes.dmyh
 gc.$(OBJEXT): {$(VPATH)}probes.h
 gc.$(OBJEXT): {$(VPATH)}ractor.h
-gc.$(OBJEXT): {$(VPATH)}ractor_pub.h
+gc.$(OBJEXT): {$(VPATH)}ractor_core.h
 gc.$(OBJEXT): {$(VPATH)}re.h
 gc.$(OBJEXT): {$(VPATH)}regenc.h
 gc.$(OBJEXT): {$(VPATH)}regex.h
@@ -6744,7 +6743,7 @@ io.$(OBJEXT): {$(VPATH)}missing.h
 io.$(OBJEXT): {$(VPATH)}node.h
 io.$(OBJEXT): {$(VPATH)}onigmo.h
 io.$(OBJEXT): {$(VPATH)}oniguruma.h
-io.$(OBJEXT): {$(VPATH)}ractor_pub.h
+io.$(OBJEXT): {$(VPATH)}ractor.h
 io.$(OBJEXT): {$(VPATH)}ruby_assert.h
 io.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 io.$(OBJEXT): {$(VPATH)}st.h
@@ -9756,7 +9755,7 @@ parse.$(OBJEXT): {$(VPATH)}parse.h
 parse.$(OBJEXT): {$(VPATH)}parse.y
 parse.$(OBJEXT): {$(VPATH)}probes.dmyh
 parse.$(OBJEXT): {$(VPATH)}probes.h
-parse.$(OBJEXT): {$(VPATH)}ractor_pub.h
+parse.$(OBJEXT): {$(VPATH)}ractor.h
 parse.$(OBJEXT): {$(VPATH)}regenc.h
 parse.$(OBJEXT): {$(VPATH)}regex.h
 parse.$(OBJEXT): {$(VPATH)}ruby_assert.h
@@ -10179,7 +10178,7 @@ process.$(OBJEXT): {$(VPATH)}node.h
 process.$(OBJEXT): {$(VPATH)}onigmo.h
 process.$(OBJEXT): {$(VPATH)}oniguruma.h
 process.$(OBJEXT): {$(VPATH)}process.c
-process.$(OBJEXT): {$(VPATH)}ractor_pub.h
+process.$(OBJEXT): {$(VPATH)}ractor.h
 process.$(OBJEXT): {$(VPATH)}ruby_assert.h
 process.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 process.$(OBJEXT): {$(VPATH)}st.h
@@ -10384,7 +10383,7 @@ ractor.$(OBJEXT): {$(VPATH)}ractor.c
 ractor.$(OBJEXT): {$(VPATH)}ractor.h
 ractor.$(OBJEXT): {$(VPATH)}ractor.rb
 ractor.$(OBJEXT): {$(VPATH)}ractor.rbinc
-ractor.$(OBJEXT): {$(VPATH)}ractor_pub.h
+ractor.$(OBJEXT): {$(VPATH)}ractor_core.h
 ractor.$(OBJEXT): {$(VPATH)}ruby_assert.h
 ractor.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 ractor.$(OBJEXT): {$(VPATH)}st.h
@@ -14180,7 +14179,7 @@ thread.$(OBJEXT): {$(VPATH)}node.h
 thread.$(OBJEXT): {$(VPATH)}onigmo.h
 thread.$(OBJEXT): {$(VPATH)}oniguruma.h
 thread.$(OBJEXT): {$(VPATH)}ractor.h
-thread.$(OBJEXT): {$(VPATH)}ractor_pub.h
+thread.$(OBJEXT): {$(VPATH)}ractor_core.h
 thread.$(OBJEXT): {$(VPATH)}ruby_assert.h
 thread.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 thread.$(OBJEXT): {$(VPATH)}st.h
@@ -14738,7 +14737,6 @@ transient_heap.$(OBJEXT): {$(VPATH)}internal/xmalloc.h
 transient_heap.$(OBJEXT): {$(VPATH)}method.h
 transient_heap.$(OBJEXT): {$(VPATH)}missing.h
 transient_heap.$(OBJEXT): {$(VPATH)}node.h
-transient_heap.$(OBJEXT): {$(VPATH)}ractor_pub.h
 transient_heap.$(OBJEXT): {$(VPATH)}ruby_assert.h
 transient_heap.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 transient_heap.$(OBJEXT): {$(VPATH)}st.h
@@ -15106,7 +15104,7 @@ variable.$(OBJEXT): {$(VPATH)}node.h
 variable.$(OBJEXT): {$(VPATH)}onigmo.h
 variable.$(OBJEXT): {$(VPATH)}oniguruma.h
 variable.$(OBJEXT): {$(VPATH)}ractor.h
-variable.$(OBJEXT): {$(VPATH)}ractor_pub.h
+variable.$(OBJEXT): {$(VPATH)}ractor_core.h
 variable.$(OBJEXT): {$(VPATH)}ruby_assert.h
 variable.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 variable.$(OBJEXT): {$(VPATH)}st.h
@@ -15520,7 +15518,7 @@ vm.$(OBJEXT): {$(VPATH)}probes.dmyh
 vm.$(OBJEXT): {$(VPATH)}probes.h
 vm.$(OBJEXT): {$(VPATH)}probes_helper.h
 vm.$(OBJEXT): {$(VPATH)}ractor.h
-vm.$(OBJEXT): {$(VPATH)}ractor_pub.h
+vm.$(OBJEXT): {$(VPATH)}ractor_core.h
 vm.$(OBJEXT): {$(VPATH)}ruby_assert.h
 vm.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 vm.$(OBJEXT): {$(VPATH)}st.h
@@ -15912,7 +15910,7 @@ vm_dump.$(OBJEXT): {$(VPATH)}missing.h
 vm_dump.$(OBJEXT): {$(VPATH)}node.h
 vm_dump.$(OBJEXT): {$(VPATH)}procstat_vm.c
 vm_dump.$(OBJEXT): {$(VPATH)}ractor.h
-vm_dump.$(OBJEXT): {$(VPATH)}ractor_pub.h
+vm_dump.$(OBJEXT): {$(VPATH)}ractor_core.h
 vm_dump.$(OBJEXT): {$(VPATH)}ruby_assert.h
 vm_dump.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 vm_dump.$(OBJEXT): {$(VPATH)}st.h
@@ -16108,7 +16106,7 @@ vm_sync.$(OBJEXT): {$(VPATH)}missing.h
 vm_sync.$(OBJEXT): {$(VPATH)}node.h
 vm_sync.$(OBJEXT): {$(VPATH)}procstat_vm.c
 vm_sync.$(OBJEXT): {$(VPATH)}ractor.h
-vm_sync.$(OBJEXT): {$(VPATH)}ractor_pub.h
+vm_sync.$(OBJEXT): {$(VPATH)}ractor_core.h
 vm_sync.$(OBJEXT): {$(VPATH)}ruby_assert.h
 vm_sync.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 vm_sync.$(OBJEXT): {$(VPATH)}st.h
diff --git a/cont.c b/cont.c
index 88ce28b1af..6c26885fef 100644
--- a/cont.c
+++ b/cont.c
@@ -29,7 +29,7 @@
 #include "mjit.h"
 #include "vm_core.h"
 #include "id_table.h"
-#include "ractor.h"
+#include "ractor_core.h"
 
 static const int DEBUG = 0;
 
diff --git a/debug.c b/debug.c
index cc6a98a906..deec382fa4 100644
--- a/debug.c
+++ b/debug.c
@@ -26,7 +26,7 @@
 #include "vm_debug.h"
 #include "vm_callinfo.h"
 #include "ruby/thread_native.h"
-#include "ractor.h"
+#include "ractor_core.h"
 
 /* This is the only place struct RIMemo is actually used */
 struct RIMemo {
diff --git a/encoding.c b/encoding.c
index 7336421862..e1441caec2 100644
--- a/encoding.c
+++ b/encoding.c
@@ -26,7 +26,6 @@
 #include "ruby/encoding.h"
 #include "ruby/util.h"
 #include "ruby_assert.h"
-#include "ractor_pub.h"
 #include "vm_sync.h"
 
 #ifndef ENC_DEBUG
diff --git a/eval.c b/eval.c
index a77fb660bc..be1337601f 100644
--- a/eval.c
+++ b/eval.c
@@ -37,7 +37,7 @@
 #include "probes_helper.h"
 #include "ruby/vm.h"
 #include "vm_core.h"
-#include "ractor.h"
+#include "ractor_core.h"
 
 NORETURN(void rb_raise_jump(VALUE, VALUE));
 void rb_ec_clear_current_thread_trace_func(const rb_execution_context_t *ec);
diff --git a/ext/ripper/depend b/ext/ripper/depend
index bfd6738928..4ce522fbc3 100644
--- a/ext/ripper/depend
+++ b/ext/ripper/depend
@@ -210,6 +210,7 @@ ripper.o: $(hdrdir)/ruby/io.h
 ripper.o: $(hdrdir)/ruby/missing.h
 ripper.o: $(hdrdir)/ruby/onigmo.h
 ripper.o: $(hdrdir)/ruby/oniguruma.h
+ripper.o: $(hdrdir)/ruby/ractor.h
 ripper.o: $(hdrdir)/ruby/regex.h
 ripper.o: $(hdrdir)/ruby/ruby.h
 ripper.o: $(hdrdir)/ruby/st.h
@@ -244,7 +245,6 @@ ripper.o: $(top_srcdir)/internal/variable.h
 ripper.o: $(top_srcdir)/internal/vm.h
 ripper.o: $(top_srcdir)/internal/warnings.h
 ripper.o: $(top_srcdir)/node.h
-ripper.o: $(top_srcdir)/ractor_pub.h
 ripper.o: $(top_srcdir)/regenc.h
 ripper.o: $(top_srcdir)/ruby_assert.h
 ripper.o: $(top_srcdir)/symbol.h
diff --git a/gc.c b/gc.c
index a41160abe6..3dbeeece72 100644
--- a/gc.c
+++ b/gc.c
@@ -112,7 +112,7 @@
 #include "vm_core.h"
 #include "vm_sync.h"
 #include "vm_callinfo.h"
-#include "ractor.h"
+#include "ractor_core.h"
 
 #include "builtin.h"
 
diff --git a/include/ruby/ractor.h b/include/ruby/ractor.h
new file mode 100644
index 0000000000..6908c0a453
--- /dev/null
+++ b/include/ruby/ractor.h
@@ -0,0 +1,45 @@
+#ifndef RUBY_RACTOR_H
+#define RUBY_RACTOR_H 1
+
+/**
+ * @file
+ * @author Koichi Sasada
+ * @date Tue Nov 17 16:39:15 2020
+ * @copyright Copyright (C) 2020 Yukihiro Matsumoto
+ * @copyright  This  file  is   a  part  of  the   programming  language  Ruby.
+ *             Permission  is hereby  granted,  to  either redistribute  and/or
+ *             modify this file, provided that  the conditions mentioned in the
+ *             file COPYING are met.  Consult the file for details.
+ */
+
+RUBY_SYMBOL_EXPORT_BEGIN
+RUBY_EXTERN VALUE rb_cRactor;
+
+VALUE rb_ractor_stdin(void);
+VALUE rb_ractor_stdout(void);
+VALUE rb_ractor_stderr(void);
+void rb_ractor_stdin_set(VALUE);
+void rb_ractor_stdout_set(VALUE);
+void rb_ractor_stderr_set(VALUE);
+
+bool rb_ractor_shareable_p_continue(VALUE obj); // do not call it directly.
+
+RUBY_SYMBOL_EXPORT_END
+
+#define RB_OBJ_SHAREABLE_P(obj) FL_TEST_RAW((obj), RUBY_FL_SHAREABLE)
+
+static inline bool
+rb_ractor_shareable_p(VALUE obj)
+{
+    if (SPECIAL_CONST_P(obj)) {
+        return true;
+    }
+    else if (RB_OBJ_SHAREABLE_P(obj)) {
+        return true;
+    }
+    else {
+        return rb_ractor_shareable_p_continue(obj);
+    }
+}
+
+#endif /* RUBY_RACTOR_H */
diff --git a/include/ruby/thread_native.h b/include/ruby/thread_native.h
index 0285c8ff40..7e08c2e97f 100644
--- a/include/ruby/thread_native.h
+++ b/include/ruby/thread_native.h
@@ -31,10 +31,14 @@ typedef union rb_thread_lock_union {
     CRITICAL_SECTION crit;
 } rb_nativethread_lock_t;
 
+typedef struct rb_thread_cond_struct rb_nativethread_cond_t;
+
 #elif defined(HAVE_PTHREAD_H)
+
 #include <pthread.h>
 typedef pthread_t rb_nativethread_id_t;
 typedef pthread_mutex_t rb_nativethread_lock_t;
+typedef pthread_cond_t rb_nativethread_cond_t;
 
 #else
 #error "unsupported thread type"
@@ -50,6 +54,19 @@ void rb_nativethread_lock_destroy(rb_nativethread_lock_t *lock);
 void rb_nativethread_lock_lock(rb_nativethread_lock_t *lock);
 void rb_nativethread_lock_unlock(rb_nativethread_lock_t *lock);
 
+void rb_native_mutex_lock(rb_nativethread_lock_t *lock);
+int  rb_native_mutex_trylock(rb_nativethread_lock_t *lock);
+void rb_native_mutex_unlock(rb_nativethread_lock_t *lock);
+void rb_native_mutex_initialize(rb_nativethread_lock_t *lock);
+void rb_native_mutex_destroy(rb_nativethread_lock_t *lock);
+
+void rb_native_cond_signal(rb_nativethread_cond_t *cond);
+void rb_native_cond_broadcast(rb_nativethread_cond_t *cond);
+void rb_native_cond_wait(rb_nativethread_cond_t *cond, rb_nativethread_lock_t *mutex);
+void rb_native_cond_timedwait(rb_nativethread_cond_t *cond, rb_nativethread_lock_t *mutex, unsigned long msec);
+void rb_native_cond_initialize(rb_nativethread_cond_t *cond);
+void rb_native_cond_destroy(rb_nativethread_cond_t *cond);
+
 RUBY_SYMBOL_EXPORT_END
 
 #endif
diff --git a/io.c b/io.c
index 95a4c7d35e..ca59729e7a 100644
--- a/io.c
+++ b/io.c
@@ -134,7 +134,7 @@
 #include "ruby/thread.h"
 #include "ruby/util.h"
 #include "ruby_atomic.h"
-#include "ractor_pub.h"
+#include "ruby/ractor.h"
 
 #if !USE_POLL
 #  include "vm_core.h"
diff --git a/parse.y b/parse.y
index 27da6bdcf9..9f7d1cd3b7 100644
--- a/parse.y
+++ b/parse.y
@@ -57,8 +57,8 @@ struct lex_context {
 #include "ruby/ruby.h"
 #include "ruby/st.h"
 #include "ruby/util.h"
+#include "ruby/ractor.h"
 #include "symbol.h"
-#include "ractor_pub.h"
 
 #define AREF(ary, i) RARRAY_AREF(ary, i)
 
diff --git a/process.c b/process.c
index d96d1e8374..bcb85ef12f 100644
--- a/process.c
+++ b/process.c
@@ -114,7 +114,7 @@ int initgroups(const char *, rb_gid_t);
 #include "ruby/thread.h"
 #include "ruby/util.h"
 #include "vm_core.h"
-#include "ractor_pub.h"
+#include "ruby/ractor.h"
 
 /* define system APIs */
 #ifdef _WIN32
diff --git a/ractor.c b/ractor.c
index 1e32c1b95e..226c9bbf6f 100644
--- a/ractor.c
+++ b/ractor.c
@@ -2,10 +2,11 @@
 
 #include "ruby/ruby.h"
 #include "ruby/thread.h"
+#include "ruby/ractor.h"
 #include "ruby/thread_native.h"
 #include "vm_core.h"
 #include "vm_sync.h"
-#include "ractor.h"
+#include "ractor_core.h"
 #include "internal/complex.h"
 #include "internal/error.h"
 #include "internal/hash.h"
@@ -14,7 +15,7 @@
 #include "variable.h"
 #include "gc.h"
 
-static VALUE rb_cRactor;
+VALUE rb_cRactor;
 static VALUE rb_eRactorError;
 static VALUE rb_eRactorRemoteError;
 static VALUE rb_eRactorMovedError;
diff --git a/ractor.h b/ractor_core.h
similarity index 96%
rename from ractor.h
rename to ractor_core.h
index 6e2f09f9b3..41bd14faad 100644
--- a/ractor.h
+++ b/ractor_core.h
@@ -1,8 +1,8 @@
 #include "ruby/ruby.h"
+#include "ruby/ractor.h"
 #include "vm_core.h"
 #include "id_table.h"
 #include "vm_debug.h"
-#include "ractor_pub.h"
 
 #ifndef RACTOR_CHECK_MODE
 #define RACTOR_CHECK_MODE (0 || VM_CHECK_MODE || RUBY_DEBUG)
@@ -158,6 +158,20 @@ void rb_ractor_blocking_threads_dec(rb_ractor_t *r, const char *file, int line);
 void rb_ractor_vm_barrier_interrupt_running_thread(rb_ractor_t *r);
 void rb_ractor_terminate_interrupt_main_thread(rb_ractor_t *r);
 void rb_ractor_terminate_all(void);
+bool rb_ractor_main_p_(void);
+
+RUBY_EXTERN bool ruby_multi_ractor;
+
+static inline bool
+rb_ractor_main_p(void)
+{
+    if (!ruby_multi_ractor) {
+        return true;
+    }
+    else {
+        return rb_ractor_main_p_();
+    }
+}
 
 static inline bool
 rb_ractor_status_p(rb_ractor_t *r, enum ractor_status status)
diff --git a/ractor_pub.h b/ractor_pub.h
deleted file mode 100644
index f2869276f6..0000000000
--- a/ractor_pub.h
+++ /dev/null
@@ -1,52 +0,0 @@
-#ifndef RACTOR_PUB_INCLUDED
-#define RACTOR_PUB_INCLUDED
-
-RUBY_EXTERN bool ruby_multi_ractor;
-
-bool rb_ractor_main_p_(void);
-
-static inline bool
-rb_ractor_main_p(void)
-{
-    if (!ruby_multi_ractor) {
-        return true;
-    }
-    else {
-        return rb_ractor_main_p_();
-    }
-}
-
-bool rb_ractor_shareable_p_continue(VALUE obj);
-
-#define RB_OBJ_SHAREABLE_P(obj) FL_TEST_RAW((obj), RUBY_FL_SHAREABLE)
-
-// TODO: deep frozen
-
-static inline bool
-rb_ractor_shareable_p(VALUE obj)
-{
-    if (SPECIAL_CONST_P(obj)) {
-        return true;
-    }
-    else if (RB_OBJ_SHAREABLE_P(obj)) {
-        return true;
-    }
-    else {
-        return rb_ractor_shareable_p_continue(obj);
-    }
-}
-
-VALUE rb_ractor_make_shareable(VALUE obj);
-
-RUBY_SYMBOL_EXPORT_BEGIN
-
-VALUE rb_ractor_stdin(void);
-VALUE rb_ractor_stdout(void);
-VALUE rb_ractor_stderr(void);
-void rb_ractor_stdin_set(VALUE);
-void rb_ractor_stdout_set(VALUE);
-void rb_ractor_stderr_set(VALUE);
-
-RUBY_SYMBOL_EXPORT_END
-
-#endif
diff --git a/thread.c b/thread.c
index ad1f4764bb..674737640f 100644
--- a/thread.c
+++ b/thread.c
@@ -94,7 +94,7 @@
 #include "ruby/thread_native.h"
 #include "timev.h"
 #include "vm_core.h"
-#include "ractor.h"
+#include "ractor_core.h"
 #include "vm_debug.h"
 #include "vm_sync.h"
 
diff --git a/thread_pthread.h b/thread_pthread.h
index fa375b3e55..1d6ea1385f 100644
--- a/thread_pthread.h
+++ b/thread_pthread.h
@@ -17,8 +17,6 @@
 #define RB_NATIVETHREAD_LOCK_INIT PTHREAD_MUTEX_INITIALIZER
 #define RB_NATIVETHREAD_COND_INIT PTHREAD_COND_INITIALIZER
 
-typedef pthread_cond_t rb_nativethread_cond_t;
-
 typedef struct native_thread_data_struct {
     union {
         struct list_node ubf;
@@ -39,18 +37,6 @@ typedef struct native_thread_data_struct {
     } cond;
 } native_thread_data_t;
 
-void rb_native_mutex_lock(rb_nativethread_lock_t *lock);
-int  rb_native_mutex_trylock(rb_nativethread_lock_t *lock);
-void rb_native_mutex_unlock(rb_nativethread_lock_t *lock);
-void rb_native_mutex_initialize(rb_nativethread_lock_t *lock);
-void rb_native_mutex_destroy(rb_nativethread_lock_t *lock);
-void rb_native_cond_signal(rb_nativethread_cond_t *cond);
-void rb_native_cond_broadcast(rb_nativethread_cond_t *cond);
-void rb_native_cond_wait(rb_nativethread_cond_t *cond, rb_nativethread_lock_t *mutex);
-void rb_native_cond_timedwait(rb_nativethread_cond_t *cond, rb_nativethread_lock_t *mutex, unsigned long msec);
-void rb_native_cond_initialize(rb_nativethread_cond_t *cond);
-void rb_native_cond_destroy(rb_nativethread_cond_t *cond);
-
 #undef except
 #undef try
 #undef leave
diff --git a/thread_win32.c b/thread_win32.c
index 132e52cae3..f4b4ea214c 100644
--- a/thread_win32.c
+++ b/thread_win32.c
@@ -52,12 +52,12 @@ w32_error(const char *func)
 }
 
 static int
-w32_mutex_lock(HANDLE lock)
+w32_mutex_lock(HANDLE lock, bool try)
 {
     DWORD result;
     while (1) {
         thread_debug("rb_native_mutex_lock: %p\n", lock);
-	result = w32_wait_events(&lock, 1, INFINITE, 0);
+        result = w32_wait_events(&lock, 1, try ? 0 : INFINITE, 0);
 	switch (result) {
 	  case WAIT_OBJECT_0:
 	    /* get mutex object */
@@ -70,7 +70,7 @@ w32_mutex_lock(HANDLE lock)
 	    return 0;
 	  case WAIT_TIMEOUT:
 	    thread_debug("timeout mutex: %p\n", lock);
-	    break;
+            return EBUSY;
 	  case WAIT_ABANDONED:
 	    rb_bug("win32_mutex_lock: WAIT_ABANDONED");
 	    break;
@@ -97,7 +97,7 @@ w32_mutex_create(void)
 static void
 gvl_acquire(rb_global_vm_lock_t *gvl, rb_thread_t *th)
 {
-    w32_mutex_lock(gvl->lock);
+    w32_mutex_lock(gvl->lock, false);
     if (GVL_DEBUG) fprintf(stderr, "gvl acquire (%p): acquire\n", th);
 }
 
@@ -323,12 +323,22 @@ void
 rb_native_mutex_lock(rb_nativethread_lock_t *lock)
 {
 #if USE_WIN32_MUTEX
-    w32_mutex_lock(lock->mutex);
+    w32_mutex_lock(lock->mutex, false);
 #else
     EnterCriticalSection(&lock->crit);
 #endif
 }
 
+int
+rb_native_mutex_trylock(rb_nativethread_lock_t *lock)
+{
+#if USE_WIN32_MUTEX
+    return w32_mutex_lock(lock->mutex, true);
+#else
+    return TryEnterCriticalSection(&lock->crit) == 0 ? EBUSY : 0;
+#endif
+}
+
 void
 rb_native_mutex_unlock(rb_nativethread_lock_t *lock)
 {
@@ -340,27 +350,6 @@ rb_native_mutex_unlock(rb_nativethread_lock_t *lock)
 #endif
 }
 
-RBIMPL_ATTR_MAYBE_UNUSED()
-static int
-native_mutex_trylock(rb_nativethread_lock_t *lock)
-{
-#if USE_WIN32_MUTEX
-    int result;
-    thread_debug("native_mutex_trylock: %p\n", lock->mutex);
-    result = w32_wait_events(&lock->mutex, 1, 1, 0);
-    thread_debug("native_mutex_trylock result: %d\n", result);
-    switch (result) {
-      case WAIT_OBJECT_0:
-	return 0;
-      case WAIT_TIMEOUT:
-	return EBUSY;
-    }
-    return EINVAL;
-#else
-    return TryEnterCriticalSection(&lock->crit) == 0;
-#endif
-}
-
 void
 rb_native_mutex_initialize(rb_nativethread_lock_t *lock)
 {
diff --git a/thread_win32.h b/thread_win32.h
index bc8eea7801..f0294ee7f6 100644
--- a/thread_win32.h
+++ b/thread_win32.h
@@ -54,17 +54,6 @@ native_tls_set(native_tls_key_t key, void *ptr)
     }
 }
 
-void rb_native_mutex_lock(rb_nativethread_lock_t *lock);
-void rb_native_mutex_unlock(rb_nativethread_lock_t *lock);
-void rb_native_mutex_initialize(rb_nativethread_lock_t *lock);
-void rb_native_mutex_destroy(rb_nativethread_lock_t *lock);
-void rb_native_cond_signal(rb_nativethread_cond_t *cond);
-void rb_native_cond_broadcast(rb_nativethread_cond_t *cond);
-void rb_native_cond_wait(rb_nativethread_cond_t *cond, rb_nativethread_lock_t *mutex);
-void rb_native_cond_timedwait(rb_nativethread_cond_t *cond, rb_nativethread_lock_t *mutex, unsigned long msec);
-void rb_native_cond_initialize(rb_nativethread_cond_t *cond);
-void rb_native_cond_destroy(rb_nativethread_cond_t *cond);
-
 RUBY_SYMBOL_EXPORT_BEGIN
 RUBY_EXTERN native_tls_key_t ruby_current_ec_key;
 RUBY_SYMBOL_EXPORT_END
diff --git a/variable.c b/variable.c
index 3cead4bc92..9f9813319e 100644
--- a/variable.c
+++ b/variable.c
@@ -36,7 +36,7 @@
 #include "transient_heap.h"
 #include "variable.h"
 #include "vm_core.h"
-#include "ractor_pub.h"
+#include "ractor_core.h"
 #include "vm_sync.h"
 
 typedef void rb_gvar_compact_t(void *var);
diff --git a/vm.c b/vm.c
index f3a6803ee0..040f0a92eb 100644
--- a/vm.c
+++ b/vm.c
@@ -35,7 +35,7 @@
 #include "vm_debug.h"
 #include "vm_exec.h"
 #include "vm_insnhelper.h"
-#include "ractor.h"
+#include "ractor_core.h"
 #include "vm_sync.h"
 
 #include "builtin.h"
diff --git a/vm_dump.c b/vm_dump.c
index 88c3207176..15b1b4a4a3 100644
--- a/vm_dump.c
+++ b/vm_dump.c
@@ -35,7 +35,7 @@
 #include "internal/vm.h"
 #include "iseq.h"
 #include "vm_core.h"
-#include "ractor.h"
+#include "ractor_core.h"
 
 #define MAX_POSBUF 128
 
diff --git a/vm_sync.c b/vm_sync.c
index 1b9897d807..1ab6c9055a 100644
--- a/vm_sync.c
+++ b/vm_sync.c
@@ -1,6 +1,6 @@
 #include "vm_core.h"
 #include "vm_sync.h"
-#include "ractor.h"
+#include "ractor_core.h"
 #include "vm_debug.h"
 #include "gc.h"