diff --git a/signal.c b/signal.c
index 27ff442bb6..cbeb6c5fe5 100644
--- a/signal.c
+++ b/signal.c
@@ -286,6 +286,7 @@ esignal_signo(VALUE self)
     return rb_iv_get(self, "signo");
 }
 
+/* :nodoc: */
 static VALUE
 interrupt_init(int argc, VALUE *argv, VALUE self)
 {