diff --git a/test/benchmark-ping-pongs.c b/test/benchmark-ping-pongs.c
index e1de83df..4518ef8d 100644
--- a/test/benchmark-ping-pongs.c
+++ b/test/benchmark-ping-pongs.c
@@ -174,7 +174,7 @@ static void pinger_connect_cb(uv_connect_t* req, int status) {
 }
 
 
-static void pinger_new() {
+static void pinger_new(void) {
   int r;
   struct sockaddr_in client_addr = uv_ip4_addr("0.0.0.0", 0);
   struct sockaddr_in server_addr = uv_ip4_addr("127.0.0.1", TEST_PORT);
diff --git a/test/benchmark-pump.c b/test/benchmark-pump.c
index 23944253..8ad9f4fa 100644
--- a/test/benchmark-pump.c
+++ b/test/benchmark-pump.c
@@ -117,7 +117,7 @@ static void show_stats(uv_timer_t* handle, int status) {
 }
 
 
-static void read_show_stats() {
+static void read_show_stats(void) {
   int64_t diff;
 
   uv_update_time(loop);
@@ -149,7 +149,7 @@ void read_sockets_close_cb(uv_handle_t* handle) {
 }
 
 
-static void start_stats_collection() {
+static void start_stats_collection(void) {
   int r;
 
   /* Show-stats timer */
@@ -231,7 +231,7 @@ static void connect_cb(uv_connect_t* req, int status) {
 }
 
 
-static void maybe_connect_some() {
+static void maybe_connect_some(void) {
   uv_connect_t* req;
   uv_tcp_t* tcp;
   uv_pipe_t* pipe;
@@ -302,7 +302,7 @@ typedef struct req_list_s {
 static req_list_t* req_freelist = NULL;
 
 
-static uv_req_t* req_alloc() {
+static uv_req_t* req_alloc(void) {
   req_list_t* req;
 
   req = req_freelist;
diff --git a/test/benchmark-spawn.c b/test/benchmark-spawn.c
index 43a71834..b78fd7e8 100644
--- a/test/benchmark-spawn.c
+++ b/test/benchmark-spawn.c
@@ -100,7 +100,7 @@ void on_read(uv_stream_t* pipe, ssize_t nread, uv_buf_t buf) {
 }
 
 
-static void spawn() {
+static void spawn(void) {
   uv_stdio_container_t stdio[2];
   int r;
 
diff --git a/test/runner-unix.c b/test/runner-unix.c
index f6ea45e1..267cc7cb 100644
--- a/test/runner-unix.c
+++ b/test/runner-unix.c
@@ -313,7 +313,7 @@ void process_cleanup(process_info_t *p) {
 
 
 /* Move the console cursor one line up and back to the first column. */
-void rewind_cursor() {
+void rewind_cursor(void) {
   fprintf(stderr, "\033[2K\r");
 }
 
diff --git a/test/runner.h b/test/runner.h
index e1bd83bc..3919007b 100644
--- a/test/runner.h
+++ b/test/runner.h
@@ -38,7 +38,7 @@
 typedef struct {
   char *task_name;
   char *process_name;
-  int (*main)();
+  int (*main)(void);
   int is_helper;
   int show_output;
 } task_entry_t, bench_entry_t;
@@ -55,7 +55,7 @@ typedef struct {
   };
 
 #define TEST_DECLARE(name)                          \
-  int run_test_##name();
+  int run_test_##name(void);
 
 #define TEST_ENTRY(name)                            \
     { #name, #name, &run_test_##name, 0, 0 },
@@ -64,13 +64,13 @@ typedef struct {
     { #name, #name, &run_test_##name, 0, 1 },
 
 #define BENCHMARK_DECLARE(name)                     \
-  int run_benchmark_##name();
+  int run_benchmark_##name(void);
 
 #define BENCHMARK_ENTRY(name)                       \
     { #name, #name, &run_benchmark_##name, 0, 0 },
 
 #define HELPER_DECLARE(name)                        \
-  int run_helper_##name();
+  int run_helper_##name(void);
 
 #define HELPER_ENTRY(task_name, name)               \
     { #task_name, #name, &run_helper_##name, 1, 0 },
@@ -123,7 +123,7 @@ void print_tests(FILE* stream);
  */
 
 /* Do platform-specific initialization. */
-void platform_init();
+void platform_init(int argc, char** argv);
 
 /* Invoke "argv[0] test-name [test-part]". Store process info in *p. */
 /* Make sure that all stdio output of the processes is buffered up. */
@@ -154,6 +154,6 @@ int process_reap(process_info_t *p);
 void process_cleanup(process_info_t *p);
 
 /* Move the console cursor one line up and back to the first column. */
-void rewind_cursor();
+void rewind_cursor(void);
 
 #endif /* RUNNER_H_ */
diff --git a/test/task.h b/test/task.h
index b351c423..de7c80ec 100644
--- a/test/task.h
+++ b/test/task.h
@@ -79,8 +79,6 @@ typedef enum {
     abort();                                              \
   } while (0)
 
-
-
 /* Have our own assert, so we are sure it does not get optimized away in
  * a release build.
  */
@@ -103,15 +101,17 @@ typedef enum {
   uv_loop_delete(uv_default_loop())
 
 /* Just sugar for wrapping the main() for a task or helper. */
-#define TEST_IMPL(name)   \
-  int run_test_##name()
+#define TEST_IMPL(name)                                                       \
+  int run_test_##name(void);                                                  \
+  int run_test_##name(void)
 
-#define BENCHMARK_IMPL(name)  \
-  int run_benchmark_##name()
-
-#define HELPER_IMPL(name)  \
-  int run_helper_##name()
+#define BENCHMARK_IMPL(name)                                                  \
+  int run_benchmark_##name(void);                                             \
+  int run_benchmark_##name(void)
 
+#define HELPER_IMPL(name)                                                     \
+  int run_helper_##name(void);                                                \
+  int run_helper_##name(void)
 
 /* Pause the calling thread for a number of milliseconds. */
 void uv_sleep(int msec);
diff --git a/test/test-delayed-accept.c b/test/test-delayed-accept.c
index 064fb6a6..a5e09f9b 100644
--- a/test/test-delayed-accept.c
+++ b/test/test-delayed-accept.c
@@ -100,7 +100,7 @@ static void connection_cb(uv_stream_t* tcp, int status) {
 }
 
 
-static void start_server() {
+static void start_server(void) {
   struct sockaddr_in addr = uv_ip4_addr("0.0.0.0", TEST_PORT);
   uv_tcp_t* server = (uv_tcp_t*)malloc(sizeof *server);
   int r;
@@ -153,7 +153,7 @@ static void connect_cb(uv_connect_t* req, int status) {
 }
 
 
-static void client_connect() {
+static void client_connect(void) {
   struct sockaddr_in addr = uv_ip4_addr("127.0.0.1", TEST_PORT);
   uv_tcp_t* client = (uv_tcp_t*)malloc(sizeof *client);
   uv_connect_t* connect_req = malloc(sizeof *connect_req);
diff --git a/test/test-getsockname.c b/test/test-getsockname.c
index 043c891c..7e2ae69a 100644
--- a/test/test-getsockname.c
+++ b/test/test-getsockname.c
@@ -165,7 +165,7 @@ static void on_connect(uv_connect_t* req, int status) {
 }
 
 
-static int tcp_listener() {
+static int tcp_listener(void) {
   struct sockaddr_in addr = uv_ip4_addr("0.0.0.0", server_port);
   struct sockaddr sockname, peername;
   int namelen;
@@ -206,7 +206,7 @@ static int tcp_listener() {
 }
 
 
-static void tcp_connector() {
+static void tcp_connector(void) {
   struct sockaddr_in server_addr = uv_ip4_addr("127.0.0.1", server_port);
   struct sockaddr sockname;
   int r, namelen;
@@ -261,7 +261,7 @@ static void udp_send(uv_udp_send_t* req, int status) {
 }
 
 
-static int udp_listener() {
+static int udp_listener(void) {
   struct sockaddr_in addr = uv_ip4_addr("0.0.0.0", server_port);
   struct sockaddr sockname;
   int namelen;
diff --git a/test/test-ipc.c b/test/test-ipc.c
index c37d1518..ff71b0ab 100644
--- a/test/test-ipc.c
+++ b/test/test-ipc.c
@@ -108,7 +108,7 @@ static void connect_cb(uv_connect_t* req, int status) {
 }
 
 
-static void make_many_connections() {
+static void make_many_connections(void) {
   tcp_conn* conn;
   struct sockaddr_in addr;
   int r, i;
@@ -578,7 +578,7 @@ int ipc_helper(int listen_after_write) {
 }
 
 
-int ipc_helper_tcp_connection() {
+int ipc_helper_tcp_connection(void) {
   /*
    * This is launched from test-ipc.c. stdin is a duplex channel that we
    * over which a handle will be transmitted.
diff --git a/test/test-multiple-listen.c b/test/test-multiple-listen.c
index 18197d18..aced132f 100644
--- a/test/test-multiple-listen.c
+++ b/test/test-multiple-listen.c
@@ -44,7 +44,7 @@ static void connection_cb(uv_stream_t* tcp, int status) {
 }
 
 
-static void start_server() {
+static void start_server(void) {
   struct sockaddr_in addr = uv_ip4_addr("0.0.0.0", TEST_PORT);
   int r;
 
@@ -71,7 +71,7 @@ static void connect_cb(uv_connect_t* req, int status) {
 }
 
 
-static void client_connect() {
+static void client_connect(void) {
   struct sockaddr_in addr = uv_ip4_addr("127.0.0.1", TEST_PORT);
   uv_connect_t* connect_req = malloc(sizeof *connect_req);
   int r;
diff --git a/test/test-ping-pong.c b/test/test-ping-pong.c
index a7b31c73..40c47f2c 100644
--- a/test/test-ping-pong.c
+++ b/test/test-ping-pong.c
@@ -145,7 +145,7 @@ static void pinger_on_connect(uv_connect_t *req, int status) {
 
 
 /* same ping-pong test, but using IPv6 connection */
-static void tcp_pinger_v6_new() {
+static void tcp_pinger_v6_new(void) {
   int r;
   struct sockaddr_in6 server_addr = uv_ip6_addr("::1", TEST_PORT);
   pinger_t *pinger;
@@ -170,7 +170,7 @@ static void tcp_pinger_v6_new() {
 }
 
 
-static void tcp_pinger_new() {
+static void tcp_pinger_new(void) {
   int r;
   struct sockaddr_in server_addr = uv_ip4_addr("127.0.0.1", TEST_PORT);
   pinger_t *pinger;
@@ -195,7 +195,7 @@ static void tcp_pinger_new() {
 }
 
 
-static void pipe_pinger_new() {
+static void pipe_pinger_new(void) {
   int r;
   pinger_t *pinger;
 
diff --git a/test/test-poll.c b/test/test-poll.c
index eb5cb848..039e95c5 100644
--- a/test/test-poll.c
+++ b/test/test-poll.c
@@ -72,7 +72,7 @@ static int valid_writable_wakeups = 0;
 static int spurious_writable_wakeups = 0;
 
 
-static int got_eagain() {
+static int got_eagain(void) {
 #ifdef _WIN32
   return WSAGetLastError() == WSAEWOULDBLOCK;
 #else
@@ -495,7 +495,7 @@ static void server_poll_cb(uv_poll_t* handle, int status, int events) {
 }
 
 
-static void start_server() {
+static void start_server(void) {
   uv_os_sock_t sock;
   server_context_t* context;
   int r;
@@ -511,7 +511,7 @@ static void start_server() {
 }
 
 
-static void start_client() {
+static void start_client(void) {
   uv_os_sock_t sock;
   connection_context_t* context;
   struct sockaddr_in server_addr = uv_ip4_addr("127.0.0.1", TEST_PORT);
@@ -531,7 +531,7 @@ static void start_client() {
 }
 
 
-static void start_poll_test() {
+static void start_poll_test(void) {
   int i, r;
 
 #ifdef _WIN32
diff --git a/test/test-ref.c b/test/test-ref.c
index 027af16f..abaaf0f8 100644
--- a/test/test-ref.c
+++ b/test/test-ref.c
@@ -58,7 +58,7 @@ static void fail_cb(void) {
 }
 
 
-static void fail_cb2() {
+static void fail_cb2(void) {
   ASSERT(0 && "fail_cb2 should not have been called");
 }
 
@@ -109,7 +109,7 @@ TEST_IMPL(ref) {
 TEST_IMPL(idle_ref) {
   uv_idle_t h;
   uv_idle_init(uv_default_loop(), &h);
-  uv_idle_start(&h, fail_cb2);
+  uv_idle_start(&h, (uv_idle_cb) fail_cb2);
   uv_unref((uv_handle_t*)&h);
   uv_run(uv_default_loop());
   do_close(&h);
@@ -132,7 +132,7 @@ TEST_IMPL(async_ref) {
 TEST_IMPL(prepare_ref) {
   uv_prepare_t h;
   uv_prepare_init(uv_default_loop(), &h);
-  uv_prepare_start(&h, fail_cb2);
+  uv_prepare_start(&h, (uv_prepare_cb) fail_cb2);
   uv_unref((uv_handle_t*)&h);
   uv_run(uv_default_loop());
   do_close(&h);
@@ -144,7 +144,7 @@ TEST_IMPL(prepare_ref) {
 TEST_IMPL(check_ref) {
   uv_check_t h;
   uv_check_init(uv_default_loop(), &h);
-  uv_check_start(&h, fail_cb2);
+  uv_check_start(&h, (uv_check_cb) fail_cb2);
   uv_unref((uv_handle_t*)&h);
   uv_run(uv_default_loop());
   do_close(&h);
diff --git a/test/test-stdio-over-pipes.c b/test/test-stdio-over-pipes.c
index aeb7bd92..d412dd6f 100644
--- a/test/test-stdio-over-pipes.c
+++ b/test/test-stdio-over-pipes.c
@@ -182,7 +182,7 @@ static uv_buf_t on_read_alloc(uv_handle_t* handle, size_t suggested_size) {
 }
 
 
-int stdio_over_pipes_helper() {
+int stdio_over_pipes_helper(void) {
   /* Write several buffers to test that the write order is preserved. */
   char* buffers[] = {
     "he",