1 files changed, 1 insertions, 0 deletions
diff --git a/signal.c b/signal.c
index fcfed8d42e..53e77d9ca4 100644
--- a/signal.c
+++ b/signal.c
@@ -257,6 +257,7 @@ static VALUE
 sig_signame(VALUE recv, VALUE signo)
 {
     const char *signame = signo2signm(NUM2INT(signo));
+    if (!signame) return Qnil;
     return rb_str_new_cstr(signame);
 }