diff --git a/signal.c b/signal.c
index 35ec892f2f..bef3b2e537 100644
--- a/signal.c
+++ b/signal.c
@@ -403,7 +403,7 @@ interrupt_init(int argc, VALUE *argv, VALUE self)
 }
 
 void rb_malloc_info_show_results(void); /* gc.c */
-#ifdef POSIX_SIGNAL
+#if defined(USE_SIGALTSTACK) || defined(_WIN32)
 static void reset_sigmask(int sig);
 #endif
 
@@ -416,7 +416,7 @@ ruby_default_signal(int sig)
     rb_malloc_info_show_results();
 
     signal(sig, SIG_DFL);
-#ifdef POSIX_SIGNAL
+#if defined(USE_SIGALTSTACK) || defined(_WIN32)
     reset_sigmask(sig);
 #endif
     raise(sig);