diff --git a/sys/ddb/db_command.c b/sys/ddb/db_command.c
index 5ebcc15642a2..db6dc24774c5 100644
--- a/sys/ddb/db_command.c
+++ b/sys/ddb/db_command.c
@@ -599,7 +599,7 @@ db_kill(dummy1, dummy2, dummy3, dummy4)
 	if (!db_expression(&pid))
 		DB_ERROR(("Missing process ID\n"));
 	db_skip_to_eol();
-	if (sig < 0 || sig > _SIG_MAXSIG)
+	if (sig < 1 || sig > _SIG_MAXSIG)
 		DB_ERROR(("Signal number out of range\n"));
 
 	/*