1 files changed, 0 insertions, 2 deletions
diff --git a/ractor_core.h b/ractor_core.h
index f0bdec212f..a3bc90febf 100644
--- a/ractor_core.h
+++ b/ractor_core.h
@@ -185,8 +185,6 @@ void rb_ractor_atfork(rb_vm_t *vm, rb_thread_t *th);
 
 VALUE rb_ractor_ensure_shareable(VALUE obj, VALUE name);
 
-void rb_ractor_ensure_main_ractor(const char *msg);
-
 RUBY_SYMBOL_EXPORT_BEGIN
 bool rb_ractor_shareable_p_continue(VALUE obj);