diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index bfdfb51c7cb7b3..5db55fabc4c39c 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -673,12 +673,10 @@ static void dispatch_calls(struct batch_options *opt,
 		struct queued_cmd *cmd,
 		int nr)
 {
-	int i;
-
 	if (!opt->buffer_output)
 		die(_("flush is only for --buffer mode"));
 
-	for (i = 0; i < nr; i++)
+	for (size_t i = 0; i < nr; i++)
 		cmd[i].fn(opt, cmd[i].line, output, data);
 
 	fflush(stdout);
@@ -686,9 +684,7 @@ static void dispatch_calls(struct batch_options *opt,
 
 static void free_cmds(struct queued_cmd *cmd, size_t *nr)
 {
-	size_t i;
-
-	for (i = 0; i < *nr; i++)
+	for (size_t i = 0; i < *nr; i++)
 		FREE_AND_NULL(cmd[i].line);
 
 	*nr = 0;
@@ -714,7 +710,6 @@ static void batch_objects_command(struct batch_options *opt,
 	size_t alloc = 0, nr = 0;
 
 	while (strbuf_getdelim_strip_crlf(&input, stdin, opt->input_delim) != EOF) {
-		int i;
 		const struct parse_cmd *cmd = NULL;
 		const char *p = NULL, *cmd_end;
 		struct queued_cmd call = {0};
@@ -724,7 +719,7 @@ static void batch_objects_command(struct batch_options *opt,
 		if (isspace(*input.buf))
 			die(_("whitespace before command: '%s'"), input.buf);
 
-		for (i = 0; i < ARRAY_SIZE(commands); i++) {
+		for (size_t i = 0; i < ARRAY_SIZE(commands); i++) {
 			if (!skip_prefix(input.buf, commands[i].name, &cmd_end))
 				continue;