diff --git a/subsys/net/lib/coap/coap_server.c b/subsys/net/lib/coap/coap_server.c
index 28d5b8de47f6..e8298506c4a3 100644
--- a/subsys/net/lib/coap/coap_server.c
+++ b/subsys/net/lib/coap/coap_server.c
@@ -127,7 +127,8 @@ static int coap_service_remove_observer(const struct coap_service *service,
 
 static int coap_server_process(int sock_fd)
 {
-	uint8_t buf[CONFIG_COAP_SERVER_MESSAGE_SIZE];
+	static uint8_t buf[CONFIG_COAP_SERVER_MESSAGE_SIZE];
+
 	struct sockaddr client_addr;
 	socklen_t client_addr_len = sizeof(client_addr);
 	struct coap_service *service = NULL;