diff --git a/test/Makefile b/test/Makefile
index fd754288..8376966a 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -3,10 +3,10 @@ PROJECT_DIR := $(realpath $(CUR_DIR)/../)
 BUILD_DIR := $(PROJECT_DIR)/build
 
 # Dependencies: need to be compiled but not to run by any Makefile target
-TEST_DEPS := dev_null
+TEST_DEPS := dev_null client
 # Tests: need to be compiled and run by test-% target
 TESTS := empty env hello_world malloc mmap file getpid spawn sched pipe time \
-	truncate readdir mkdir link tls pthread uname rlimit client server \
+	truncate readdir mkdir link tls pthread uname rlimit server \
 	server_epoll unix_socket cout hostfs cpuid rdtsc device
 # Benchmarks: need to be compiled and run by bench-% target
 BENCHES := spawn_and_exit_latency pipe_throughput unix_socket_throughput
diff --git a/test/client/main.c b/test/client/main.c
index d73dfb94..ab0826f7 100644
--- a/test/client/main.c
+++ b/test/client/main.c
@@ -13,8 +13,8 @@ int main(int argc, const char *argv[]) {
 	const char* message = "Hello world!";
 	int ret;
 
-	if (argc != 2) {
-		printf("usage: ./client <ipaddress>\n");
+	if (argc != 3) {
+		printf("usage: ./client <ipaddress> <port>\n");
 		return 0;
 	}
 
@@ -27,7 +27,7 @@ int main(int argc, const char *argv[]) {
 	struct sockaddr_in servaddr;
 	memset(&servaddr, 0, sizeof(servaddr));
 	servaddr.sin_family = AF_INET;
-	servaddr.sin_port = htons(6666);
+	servaddr.sin_port = htons((uint16_t)strtol(argv[2], NULL, 10));
 
 	ret = inet_pton(AF_INET, argv[1], &servaddr.sin_addr);
 	if (ret <= 0) {
diff --git a/test/server/main.c b/test/server/main.c
index a8962926..c34eaa26 100644
--- a/test/server/main.c
+++ b/test/server/main.c
@@ -37,7 +37,7 @@ int main(int argc, const char *argv[]) {
 	}
 
 	int client_pid;
-	char* client_argv[] = {"client", "127.0.0.1", NULL};
+	char* client_argv[] = {"client", "127.0.0.1", "6666", NULL};
 	ret = posix_spawn(&client_pid, "/bin/client", NULL, NULL, client_argv, NULL);
 	if (ret < 0) {
 		printf("spawn client process error: %s(errno: %d)\n", strerror(errno), errno);
diff --git a/test/server_epoll/main.c b/test/server_epoll/main.c
index dad1ffca..30fcd92a 100644
--- a/test/server_epoll/main.c
+++ b/test/server_epoll/main.c
@@ -12,6 +12,7 @@
 #include <spawn.h>
 
 #define MAXEVENTS 64
+#define DEFAULT_PROC_NUM 3
 
 static int
 create_and_bind() {
@@ -25,7 +26,7 @@ create_and_bind() {
 	memset(&servaddr, 0, sizeof(servaddr));
 	servaddr.sin_family = AF_INET;
 	servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
-	servaddr.sin_port = htons(6666);
+	servaddr.sin_port = htons(6667);
 
 	int ret = bind(listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr));
 	if (ret < 0) {
@@ -65,18 +66,25 @@ main(int argc, char *argv[]) {
 
 	// spawn clients
 	int client_pid;
-	char* client_argv[] = {"client", "127.0.0.1", NULL};
-	for(int i=0; i<3; ++i) {
+	int proc_num = DEFAULT_PROC_NUM;
+	char* client_argv[] = {"client", "127.0.0.1", "6667", NULL};
+	for(int i=0; i<DEFAULT_PROC_NUM; ++i) {
 		int ret = posix_spawn(&client_pid, "/bin/client", NULL, NULL, client_argv, NULL);
 		if (ret < 0) {
-			printf("spawn client process error: %s(errno: %d)\n", strerror(errno), errno);
-			return -1;
+			printf("spawn client process error: %s(errno: %d), %d process(es) spawned\n", strerror(errno), errno, i);
+			if (i == 0) {
+			    perror("no client is successfully spawned");
+			    return -1;
+			} else {
+			    proc_num = i;
+			    break;
+			}
 		}
 	}
 
 	/* The event loop */
 	int done_count = 0;
-	while (done_count < 3) {
+	while (done_count < proc_num) {
 		int n = epoll_wait(efd, events, MAXEVENTS, -1);
 		for (int i = 0; i < n; i++) {
 			if ((events[i].events & EPOLLERR) ||