diff --git a/src/libthread/tsignal.c b/src/libthread/tsignal.c
new file mode 100644
index 0000000..9c64c46
--- /dev/null
+++ b/src/libthread/tsignal.c
@@ -0,0 +1,43 @@
+#include <u.h>
+#include <libc.h>
+#include <thread.h>
+
+extern int _threaddebuglevel;
+
+void
+usage(void)
+{
+	fprint(2, "usage: tsignal [-[ednf] note]*\n");
+	threadexitsall("usage");
+}
+
+void
+threadmain(int argc, char **argv)
+{
+	Channel *c;
+	char *msg;
+
+	ARGBEGIN{
+	case 'D':
+		_threaddebuglevel = ~0;
+		break;
+	default:
+		usage();
+	case 'e':
+		notifyenable(EARGF(usage()));
+		break;
+	case 'd':
+		notifydisable(EARGF(usage()));
+		break;
+	case 'n':
+		notifyon(EARGF(usage()));
+		break;
+	case 'f':
+		notifyoff(EARGF(usage()));
+		break;
+	}ARGEND
+
+	c = threadnotechan();
+	while((msg = recvp(c)) != nil)
+		print("note: %s\n", msg);
+}