diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index afd36c9c53..6882d526e6 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -465,7 +465,7 @@ static void rp_error(const char *err, ...)
 	va_end(params);
 }
 
-static int copy_to_sideband(int in, int out, void *arg)
+static int copy_to_sideband(int in, int UNUSED(out), void *UNUSED(arg))
 {
 	char data[128];
 	int keepalive_active = 0;
diff --git a/convert.c b/convert.c
index b31a25b536..25d89fa83b 100644
--- a/convert.c
+++ b/convert.c
@@ -619,7 +619,7 @@ struct filter_params {
 	const char *path;
 };
 
-static int filter_buffer_or_fd(int in, int out, void *data)
+static int filter_buffer_or_fd(int UNUSED(in), int out, void *data)
 {
 	/*
 	 * Spawn cmd and feed the buffer contents through its stdin.
diff --git a/fetch-pack.c b/fetch-pack.c
index bda9d0f433..9f2933e868 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -823,7 +823,7 @@ static int everything_local(struct fetch_pack_args *args,
 	return retval;
 }
 
-static int sideband_demux(int in, int out, void *data)
+static int sideband_demux(int UNUSED(in), int out, void *data)
 {
 	int *xd = data;
 	int ret;
diff --git a/send-pack.c b/send-pack.c
index 662f7c2aeb..7e99c64e6b 100644
--- a/send-pack.c
+++ b/send-pack.c
@@ -266,7 +266,7 @@ static int receive_status(struct packet_reader *reader, struct ref *refs)
 	return ret;
 }
 
-static int sideband_demux(int in, int out, void *data)
+static int sideband_demux(int UNUSED(in), int out, void *data)
 {
 	int *fd = data, ret;
 	if (async_with_fork())