diff --git a/netlink.c b/netlink.c
index 6cc04a0..379d46e 100644
--- a/netlink.c
+++ b/netlink.c
@@ -130,7 +130,7 @@ static uint32_t nl_send(int s, void *req, uint16_t type,
 	if (n < 0)
 		die("netlink: Failed to send(): %s", strerror(errno));
 	else if (n < len)
-		die("netlink: Short send (%lu of %lu bytes)", n, len);
+		die("netlink: Short send (%zd of %zd bytes)", n, len);
 
 	return nh->nlmsg_seq;
 }
diff --git a/packet.c b/packet.c
index 9589824..12ac76b 100644
--- a/packet.c
+++ b/packet.c
@@ -36,7 +36,7 @@ void packet_add_do(struct pool *p, size_t len, const char *start,
 	size_t idx = p->count;
 
 	if (idx >= p->size) {
-		trace("add packet index %lu to pool with size %lu, %s:%i",
+		trace("add packet index %zu to pool with size %zu, %s:%i",
 		      idx, p->size, func, line);
 		return;
 	}
@@ -48,14 +48,14 @@ void packet_add_do(struct pool *p, size_t len, const char *start,
 	}
 
 	if (start + len > p->buf + p->buf_size) {
-		trace("add packet start %p, length: %lu, buffer end %p, %s:%i",
+		trace("add packet start %p, length: %zu, buffer end %p, %s:%i",
 		      (void *)start, len, (void *)(p->buf + p->buf_size),
 		      func, line);
 		return;
 	}
 
 	if (len > UINT16_MAX) {
-		trace("add packet length %lu, %s:%i", len, func, line);
+		trace("add packet length %zu, %s:%i", len, func, line);
 		return;
 	}
 
@@ -90,7 +90,7 @@ void *packet_get_do(const struct pool *p, size_t idx, size_t offset,
 {
 	if (idx >= p->size || idx >= p->count) {
 		if (func) {
-			trace("packet %lu from pool size: %lu, count: %lu, "
+			trace("packet %zu from pool size: %zu, count: %zu, "
 			      "%s:%i", idx, p->size, p->count, func, line);
 		}
 		return NULL;
@@ -98,7 +98,7 @@ void *packet_get_do(const struct pool *p, size_t idx, size_t offset,
 
 	if (len > UINT16_MAX || len + offset > UINT32_MAX) {
 		if (func) {
-			trace("packet data length %lu, offset %lu, %s:%i",
+			trace("packet data length %zu, offset %zu, %s:%i",
 			      len, offset, func, line);
 		}
 		return NULL;
@@ -106,7 +106,7 @@ void *packet_get_do(const struct pool *p, size_t idx, size_t offset,
 
 	if (p->pkt[idx].offset + len + offset > p->buf_size) {
 		if (func) {
-			trace("packet offset plus length %lu from size %lu, "
+			trace("packet offset plus length %lu from size %zu, "
 			      "%s:%i", p->pkt[idx].offset + len + offset,
 			      p->buf_size, func, line);
 		}
@@ -115,7 +115,7 @@ void *packet_get_do(const struct pool *p, size_t idx, size_t offset,
 
 	if (len + offset > p->pkt[idx].len) {
 		if (func) {
-			trace("data length %lu, offset %lu from length %u, "
+			trace("data length %zu, offset %zu from length %u, "
 			      "%s:%i", len, offset, p->pkt[idx].len,
 			      func, line);
 		}
diff --git a/pcap.c b/pcap.c
index 524612a..501d52d 100644
--- a/pcap.c
+++ b/pcap.c
@@ -101,7 +101,7 @@ void pcap(const char *pkt, size_t len)
 
 	gettimeofday(&tv, NULL);
 	if (pcap_frame(pkt, len, &tv) != 0)
-		debug("Cannot log packet, length %lu", len);
+		debug("Cannot log packet, length %zu", len);
 }
 
 /**
@@ -123,7 +123,7 @@ void pcap_multiple(const struct iovec *iov, unsigned int n, size_t offset)
 	for (i = 0; i < n; i++) {
 		if (pcap_frame((char *)iov[i].iov_base + offset,
 			       iov[i].iov_len - offset, &tv) != 0) {
-			debug("Cannot log packet, length %lu",
+			debug("Cannot log packet, length %zu",
 			      iov->iov_len - offset);
 			return;
 		}
diff --git a/tap.c b/tap.c
index 4f11000..2ceda8d 100644
--- a/tap.c
+++ b/tap.c
@@ -191,7 +191,7 @@ void tap_udp4_send(const struct ctx *c, struct in_addr src, in_port_t sport,
 	memcpy(data, in, len);
 
 	if (tap_send(c, buf, len + (data - buf)) < 0)
-		debug("tap: failed to send %lu bytes (IPv4)", len);
+		debug("tap: failed to send %zu bytes (IPv4)", len);
 }
 
 /**
@@ -214,7 +214,7 @@ void tap_icmp4_send(const struct ctx *c, struct in_addr src, struct in_addr dst,
 	csum_icmp4(icmp4h, icmp4h + 1, len - sizeof(*icmp4h));
 
 	if (tap_send(c, buf, len + (data - buf)) < 0)
-		debug("tap: failed to send %lu bytes (IPv4)", len);
+		debug("tap: failed to send %zu bytes (IPv4)", len);
 }
 
 /**
@@ -278,7 +278,7 @@ void tap_udp6_send(const struct ctx *c,
 	memcpy(data, in, len);
 
 	if (tap_send(c, buf, len + (data - buf)) < 1)
-		debug("tap: failed to send %lu bytes (IPv6)", len);
+		debug("tap: failed to send %zu bytes (IPv6)", len);
 }
 
 /**
@@ -302,7 +302,7 @@ void tap_icmp6_send(const struct ctx *c,
 	csum_icmp6(icmp6h, src, dst, icmp6h + 1, len - sizeof(*icmp6h));
 
 	if (tap_send(c, buf, len + (data - buf)) < 1)
-		debug("tap: failed to send %lu bytes (IPv6)", len);
+		debug("tap: failed to send %zu bytes (IPv6)", len);
 }
 
 /**
@@ -364,7 +364,7 @@ static void tap_send_remainder(const struct ctx *c, const struct iovec *iov,
 		ssize_t sent = send(c->fd_tap, base + offset, len - offset,
 				    MSG_NOSIGNAL);
 		if (sent < 0) {
-			err("tap: partial frame send (missing %lu bytes): %s",
+			err("tap: partial frame send (missing %zu bytes): %s",
 			    len - offset, strerror(errno));
 			return;
 		}
@@ -433,7 +433,7 @@ size_t tap_send_frames(const struct ctx *c, const struct iovec *iov, size_t n)
 		m = tap_send_frames_pasta(c, iov, n);
 
 	if (m < n)
-		debug("tap: failed to send %lu frames of %lu", n - m, n);
+		debug("tap: failed to send %zu frames of %zu", n - m, n);
 
 	pcap_multiple(iov, m, c->mode == MODE_PASST ? sizeof(uint32_t) : 0);
 
diff --git a/tcp.c b/tcp.c
index 40e3dec..44468ca 100644
--- a/tcp.c
+++ b/tcp.c
@@ -2570,7 +2570,8 @@ int tcp_tap_handler(struct ctx *c, uint8_t pif, int af,
 		return 1;
 	}
 
-	trace("TCP: packet length %lu from tap for index %lu", len, CONN_IDX(conn));
+	trace("TCP: packet length %zu from tap for index %lu",
+	      len, CONN_IDX(conn));
 
 	if (th->rst) {
 		conn_event(c, conn, CLOSED);
diff --git a/tcp_splice.c b/tcp_splice.c
index a5c1332..0a23584 100644
--- a/tcp_splice.c
+++ b/tcp_splice.c
@@ -321,7 +321,7 @@ static int tcp_splice_connect_finish(const struct ctx *c,
 
 			if (fcntl(conn->pipe[side][0], F_SETPIPE_SZ,
 				  c->tcp.pipe_size)) {
-				trace("TCP (spliced): cannot set %d->%d pipe size to %lu",
+				trace("TCP (spliced): cannot set %d->%d pipe size to %zu",
 				      side, !side, c->tcp.pipe_size);
 			}
 		}
@@ -554,7 +554,7 @@ retry:
 		readlen = splice(conn->s[fromside], NULL,
 				 conn->pipe[fromside][1], NULL, c->tcp.pipe_size,
 				 SPLICE_F_MOVE | SPLICE_F_NONBLOCK);
-		trace("TCP (spliced): %li from read-side call", readlen);
+		trace("TCP (spliced): %zi from read-side call", readlen);
 		if (readlen < 0) {
 			if (errno == EINTR)
 				goto retry;
@@ -580,7 +580,7 @@ eintr:
 		written = splice(conn->pipe[fromside][0], NULL,
 				 conn->s[!fromside], NULL, to_write,
 				 SPLICE_F_MOVE | more | SPLICE_F_NONBLOCK);
-		trace("TCP (spliced): %li from write-side call (passed %lu)",
+		trace("TCP (spliced): %zi from write-side call (passed %zi)",
 		      written, to_write);
 
 		/* Most common case: skip updating counters. */
@@ -718,7 +718,7 @@ static void tcp_splice_pipe_refill(const struct ctx *c)
 
 		if (fcntl(splice_pipe_pool[i][0], F_SETPIPE_SZ,
 			  c->tcp.pipe_size)) {
-			trace("TCP (spliced): cannot set pool pipe size to %lu",
+			trace("TCP (spliced): cannot set pool pipe size to %zu",
 			      c->tcp.pipe_size);
 		}
 	}