diff --git a/common.mk b/common.mk
index d67057ebca..118e60d061 100644
--- a/common.mk
+++ b/common.mk
@@ -7238,6 +7238,7 @@ gc.$(OBJEXT): $(CCAN_DIR)/str/str.h
 gc.$(OBJEXT): $(hdrdir)/ruby.h
 gc.$(OBJEXT): $(hdrdir)/ruby/ruby.h
 gc.$(OBJEXT): $(hdrdir)/ruby/version.h
+gc.$(OBJEXT): $(top_srcdir)/gc/gc.h
 gc.$(OBJEXT): $(top_srcdir)/gc/gc_impl.h
 gc.$(OBJEXT): $(top_srcdir)/internal/array.h
 gc.$(OBJEXT): $(top_srcdir)/internal/basic_operators.h
@@ -7508,6 +7509,7 @@ gc_impl.$(OBJEXT): $(CCAN_DIR)/list/list.h
 gc_impl.$(OBJEXT): $(CCAN_DIR)/str/str.h
 gc_impl.$(OBJEXT): $(hdrdir)/ruby/ruby.h
 gc_impl.$(OBJEXT): $(top_srcdir)/gc/default.c
+gc_impl.$(OBJEXT): $(top_srcdir)/gc/gc.h
 gc_impl.$(OBJEXT): $(top_srcdir)/gc/gc_impl.h
 gc_impl.$(OBJEXT): $(top_srcdir)/internal/bits.h
 gc_impl.$(OBJEXT): $(top_srcdir)/internal/compilers.h
diff --git a/gc.c b/gc.c
index 3d394fb5f5..bd094ef19c 100644
--- a/gc.c
+++ b/gc.c
@@ -82,6 +82,7 @@
 #include "darray.h"
 #include "debug_counter.h"
 #include "eval_intern.h"
+#include "gc/gc.h"
 #include "gc/gc_impl.h"
 #include "id_table.h"
 #include "internal.h"
@@ -126,34 +127,6 @@
 #include "builtin.h"
 #include "shape.h"
 
-RUBY_SYMBOL_EXPORT_BEGIN
-size_t rb_size_mul_or_raise(size_t, size_t, VALUE);
-bool rb_gc_obj_free(void *objspace, VALUE obj);
-size_t rb_gc_obj_optimal_size(VALUE obj);
-void rb_gc_mark_children(void *objspace, VALUE obj);
-void rb_gc_update_object_references(void *objspace, VALUE obj);
-void rb_gc_update_vm_references(void *objspace);
-void rb_gc_reachable_objects_from_callback(VALUE obj);
-void rb_gc_event_hook(VALUE obj, rb_event_flag_t event);
-void *rb_gc_get_objspace(void);
-size_t rb_size_mul_or_raise(size_t x, size_t y, VALUE exc);
-void rb_gc_run_obj_finalizer(VALUE objid, long count, VALUE (*callback)(long i, void *data), void *data);
-void rb_gc_set_pending_interrupt(void);
-void rb_gc_unset_pending_interrupt(void);
-bool rb_gc_obj_free(void *objspace, VALUE obj);
-void rb_gc_mark_roots(void *objspace, const char **categoryp);
-void rb_gc_ractor_newobj_cache_foreach(void (*func)(void *cache, void *data), void *data);
-bool rb_gc_multi_ractor_p(void);
-void rb_objspace_reachable_objects_from_root(void (func)(const char *category, VALUE, void *), void *passing_data);
-void rb_objspace_reachable_objects_from(VALUE obj, void (func)(VALUE, void *), void *data);
-void rb_obj_info_dump(VALUE obj);
-const char *rb_obj_info(VALUE obj);
-bool rb_gc_shutdown_call_finalizer_p(VALUE obj);
-uint32_t rb_gc_get_shape(VALUE obj);
-void rb_gc_set_shape(VALUE obj, uint32_t shape_id);
-uint32_t rb_gc_rebuild_shape(VALUE obj, size_t size_pool_id);
-size_t rb_obj_memsize_of(VALUE obj);
-
 unsigned int
 rb_gc_vm_lock(void)
 {
@@ -352,7 +325,6 @@ rb_gc_rebuild_shape(VALUE obj, size_t size_pool_id)
 
     return (uint32_t)rb_shape_id(new_shape);
 }
-RUBY_SYMBOL_EXPORT_END
 
 void rb_vm_update_references(void *ptr);
 
diff --git a/gc/default.c b/gc/default.c
index 3e1491cbf5..dfd81ab148 100644
--- a/gc/default.c
+++ b/gc/default.c
@@ -23,6 +23,7 @@
 #include "ruby/internal/encoding/string.h"
 #include "ccan/list/list.h"
 #include "darray.h"
+#include "gc/gc.h"
 #include "gc/gc_impl.h"
 #include "probes.h"
 
@@ -67,41 +68,6 @@
 # include <mach/mach_port.h>
 #endif
 
-/* Headers from gc.c */
-unsigned int rb_gc_vm_lock(void);
-void rb_gc_vm_unlock(unsigned int lev);
-unsigned int rb_gc_cr_lock(void);
-void rb_gc_cr_unlock(unsigned int lev);
-unsigned int rb_gc_vm_lock_no_barrier(void);
-void rb_gc_vm_unlock_no_barrier(unsigned int lev);
-void rb_gc_vm_barrier(void);
-size_t rb_gc_obj_optimal_size(VALUE obj);
-void rb_gc_mark_children(void *objspace, VALUE obj);
-void rb_gc_update_object_references(void *objspace, VALUE obj);
-void rb_gc_update_vm_references(void *objspace);
-void rb_gc_reachable_objects_from_callback(VALUE obj);
-void rb_gc_event_hook(VALUE obj, rb_event_flag_t event);
-void *rb_gc_get_objspace(void);
-size_t rb_size_mul_or_raise(size_t x, size_t y, VALUE exc);
-void rb_gc_run_obj_finalizer(VALUE objid, long count, VALUE (*callback)(long i, void *data), void *data);
-void rb_gc_set_pending_interrupt(void);
-void rb_gc_unset_pending_interrupt(void);
-bool rb_gc_obj_free(void *objspace, VALUE obj);
-void rb_gc_mark_roots(void *objspace, const char **categoryp);
-void rb_gc_ractor_newobj_cache_foreach(void (*func)(void *cache, void *data), void *data);
-bool rb_gc_multi_ractor_p(void);
-void rb_objspace_reachable_objects_from_root(void (func)(const char *category, VALUE, void *), void *passing_data);
-void rb_objspace_reachable_objects_from(VALUE obj, void (func)(VALUE, void *), void *data);
-void rb_obj_info_dump(VALUE obj);
-const char *rb_obj_info(VALUE obj);
-bool rb_gc_shutdown_call_finalizer_p(VALUE obj);
-uint32_t rb_gc_get_shape(VALUE obj);
-void rb_gc_set_shape(VALUE obj, uint32_t shape_id);
-uint32_t rb_gc_rebuild_shape(VALUE obj, size_t size_pool_id);
-size_t rb_obj_memsize_of(VALUE obj);
-
-void rb_ractor_finish_marking(void);
-
 #ifndef VM_CHECK_MODE
 # define VM_CHECK_MODE RUBY_DEBUG
 #endif
diff --git a/gc/gc.h b/gc/gc.h
new file mode 100644
index 0000000000..5f9a7b218b
--- /dev/null
+++ b/gc/gc.h
@@ -0,0 +1,42 @@
+#ifndef GC_GC_H
+#define GC_GC_H
+
+#include "ruby/ruby.h"
+
+RUBY_SYMBOL_EXPORT_BEGIN
+unsigned int rb_gc_vm_lock(void);
+void rb_gc_vm_unlock(unsigned int lev);
+unsigned int rb_gc_cr_lock(void);
+void rb_gc_cr_unlock(unsigned int lev);
+unsigned int rb_gc_vm_lock_no_barrier(void);
+void rb_gc_vm_unlock_no_barrier(unsigned int lev);
+void rb_gc_vm_barrier(void);
+size_t rb_gc_obj_optimal_size(VALUE obj);
+void rb_gc_mark_children(void *objspace, VALUE obj);
+void rb_gc_update_object_references(void *objspace, VALUE obj);
+void rb_gc_update_vm_references(void *objspace);
+void rb_gc_reachable_objects_from_callback(VALUE obj);
+void rb_gc_event_hook(VALUE obj, rb_event_flag_t event);
+void *rb_gc_get_objspace(void);
+size_t rb_size_mul_or_raise(size_t x, size_t y, VALUE exc);
+void rb_gc_run_obj_finalizer(VALUE objid, long count, VALUE (*callback)(long i, void *data), void *data);
+void rb_gc_set_pending_interrupt(void);
+void rb_gc_unset_pending_interrupt(void);
+bool rb_gc_obj_free(void *objspace, VALUE obj);
+void rb_gc_mark_roots(void *objspace, const char **categoryp);
+void rb_gc_ractor_newobj_cache_foreach(void (*func)(void *cache, void *data), void *data);
+bool rb_gc_multi_ractor_p(void);
+void rb_objspace_reachable_objects_from_root(void (func)(const char *category, VALUE, void *), void *passing_data);
+void rb_objspace_reachable_objects_from(VALUE obj, void (func)(VALUE, void *), void *data);
+void rb_obj_info_dump(VALUE obj);
+const char *rb_obj_info(VALUE obj);
+bool rb_gc_shutdown_call_finalizer_p(VALUE obj);
+uint32_t rb_gc_get_shape(VALUE obj);
+void rb_gc_set_shape(VALUE obj, uint32_t shape_id);
+uint32_t rb_gc_rebuild_shape(VALUE obj, size_t size_pool_id);
+size_t rb_obj_memsize_of(VALUE obj);
+RUBY_SYMBOL_EXPORT_END
+
+void rb_ractor_finish_marking(void);
+
+#endif