diff --git a/signal.c b/signal.c
index 247f72ae8c..8dfeff9a50 100644
--- a/signal.c
+++ b/signal.c
@@ -1107,6 +1107,9 @@ default_handler(int sig)
 #endif
 #ifdef SIGUSR2
       case SIGUSR2:
+#endif
+#ifdef RUBY_SIGCHLD
+      case RUBY_SIGCHLD:
 #endif
         func = sighandler;
         break;