diff --git a/builtin-add.c b/builtin-add.c
index dd895dfb1d35f7e90d6529821e284d73e912d6d6..7c6a296af13b4245a701f8893cc00aa7f0a41277 100644
--- a/builtin-add.c
+++ b/builtin-add.c
@@ -138,9 +138,10 @@ static void refresh(int verbose, const char **pathspec)
 int interactive_add(int argc, const char **argv)
 {
 	int status;
-	const char **args = xmalloc(sizeof(const char *) * (argc + 1));
+	const char **args = xcalloc(sizeof(const char *), (argc + 2));
+
 	args[0] = "add--interactive";
-	memcpy((void *)args + sizeof(const char *), argv, sizeof(const char *) * argc);
+	memcpy(&(args[1]), argv, sizeof(const char *) * argc);
 	args[argc + 1] = NULL;
 
 	status = run_command_v_opt(args, RUN_GIT_CMD);