diff --git a/test/echo-server.c b/test/echo-server.c
index bfed6767..a38e975d 100644
--- a/test/echo-server.c
+++ b/test/echo-server.c
@@ -340,6 +340,7 @@ HELPER_IMPL(tcp4_echo_server) {
   if (tcp4_echo_start(TEST_PORT))
     return 1;
 
+  notify_parent_process();
   uv_run(loop, UV_RUN_DEFAULT);
   return 0;
 }
@@ -351,6 +352,7 @@ HELPER_IMPL(tcp6_echo_server) {
   if (tcp6_echo_start(TEST_PORT))
     return 1;
 
+  notify_parent_process();
   uv_run(loop, UV_RUN_DEFAULT);
   return 0;
 }
@@ -362,6 +364,7 @@ HELPER_IMPL(pipe_echo_server) {
   if (pipe_echo_start(TEST_PIPENAME))
     return 1;
 
+  notify_parent_process();
   uv_run(loop, UV_RUN_DEFAULT);
   return 0;
 }
@@ -373,6 +376,7 @@ HELPER_IMPL(udp4_echo_server) {
   if (udp4_echo_start(TEST_PORT))
     return 1;
 
+  notify_parent_process();
   uv_run(loop, UV_RUN_DEFAULT);
   return 0;
 }
diff --git a/test/run-tests.c b/test/run-tests.c
index 9b8af046..42bde0bb 100644
--- a/test/run-tests.c
+++ b/test/run-tests.c
@@ -109,20 +109,24 @@ static int maybe_run_test(int argc, char **argv) {
   }
 
   if (strcmp(argv[1], "spawn_helper1") == 0) {
+    notify_parent_process();
     return 1;
   }
 
   if (strcmp(argv[1], "spawn_helper2") == 0) {
+    notify_parent_process();
     printf("hello world\n");
     return 1;
   }
 
   if (strcmp(argv[1], "spawn_tcp_server_helper") == 0) {
+    notify_parent_process();
     return spawn_tcp_server_helper();
   }
 
   if (strcmp(argv[1], "spawn_helper3") == 0) {
     char buffer[256];
+    notify_parent_process();
     ASSERT(buffer == fgets(buffer, sizeof(buffer) - 1, stdin));
     buffer[sizeof(buffer) - 1] = '\0';
     fputs(buffer, stdout);
@@ -130,12 +134,14 @@ static int maybe_run_test(int argc, char **argv) {
   }
 
   if (strcmp(argv[1], "spawn_helper4") == 0) {
+    notify_parent_process();
     /* Never surrender, never return! */
     while (1) uv_sleep(10000);
   }
 
   if (strcmp(argv[1], "spawn_helper5") == 0) {
     const char out[] = "fourth stdio!\n";
+    notify_parent_process();
 #ifdef _WIN32
     DWORD bytes;
     WriteFile((HANDLE) _get_osfhandle(3), out, sizeof(out) - 1, &bytes, NULL);
@@ -156,6 +162,8 @@ static int maybe_run_test(int argc, char **argv) {
   if (strcmp(argv[1], "spawn_helper6") == 0) {
     int r;
 
+    notify_parent_process();
+
     r = fprintf(stdout, "hello world\n");
     ASSERT(r > 0);
 
@@ -168,6 +176,9 @@ static int maybe_run_test(int argc, char **argv) {
   if (strcmp(argv[1], "spawn_helper7") == 0) {
     int r;
     char *test;
+
+    notify_parent_process();
+
     /* Test if the test value from the parent is still set */
     test = getenv("ENV_TEST");
     ASSERT(test != NULL);
@@ -181,6 +192,8 @@ static int maybe_run_test(int argc, char **argv) {
 #ifndef _WIN32
   if (strcmp(argv[1], "spawn_helper8") == 0) {
     int fd;
+
+    notify_parent_process();
     ASSERT(sizeof(fd) == read(0, &fd, sizeof(fd)));
     ASSERT(fd > 2);
     ASSERT(-1 == write(fd, "x", 1));
@@ -190,6 +203,7 @@ static int maybe_run_test(int argc, char **argv) {
 #endif  /* !_WIN32 */
 
   if (strcmp(argv[1], "spawn_helper9") == 0) {
+    notify_parent_process();
     return spawn_stdin_stdout();
   }
 
@@ -200,6 +214,7 @@ static int maybe_run_test(int argc, char **argv) {
 
     ASSERT(uid == getuid());
     ASSERT(gid == getgid());
+    notify_parent_process();
 
     return 1;
   }
diff --git a/test/runner-unix.c b/test/runner-unix.c
index 6506fb3a..432cf33d 100644
--- a/test/runner-unix.c
+++ b/test/runner-unix.c
@@ -42,6 +42,30 @@
 
 extern char** environ;
 
+static void closefd(int fd) {
+  if (close(fd) == 0 || errno == EINTR || errno == EINPROGRESS)
+    return;
+
+  perror("close");
+  abort();
+}
+
+
+void notify_parent_process(void) {
+  char* arg;
+  int fd;
+
+  arg = getenv("UV_TEST_RUNNER_FD");
+  if (arg == NULL)
+    return;
+
+  fd = atoi(arg);
+  assert(fd > STDERR_FILENO);
+  unsetenv("UV_TEST_RUNNER_FD");
+  closefd(fd);
+}
+
+
 /* Do platform-specific initialization. */
 int platform_init(int argc, char **argv) {
   /* Disable stdio output buffering. */
@@ -65,6 +89,9 @@ int process_start(char* name, char* part, process_info_t* p, int is_helper) {
   int stdout_fd;
   const char* arg;
   char* args[16];
+  int pipefd[2];
+  char fdstr[8];
+  ssize_t rc;
   int n;
   pid_t pid;
 
@@ -94,6 +121,19 @@ int process_start(char* name, char* part, process_info_t* p, int is_helper) {
     return -1;
   }
 
+  if (is_helper) {
+    if (pipe(pipefd)) {
+      perror("pipe");
+      return -1;
+    }
+
+    snprintf(fdstr, sizeof(fdstr), "%d", pipefd[1]);
+    if (setenv("UV_TEST_RUNNER_FD", fdstr, /* overwrite */ 1)) {
+      perror("setenv");
+      return -1;
+    }
+  }
+
   p->terminated = 0;
   p->status = 0;
 
@@ -106,6 +146,8 @@ int process_start(char* name, char* part, process_info_t* p, int is_helper) {
 
   if (pid == 0) {
     /* child */
+    if (is_helper)
+      closefd(pipefd[0]);
     dup2(stdout_fd, STDOUT_FILENO);
     dup2(stdout_fd, STDERR_FILENO);
     execve(args[0], args, environ);
@@ -118,6 +160,28 @@ int process_start(char* name, char* part, process_info_t* p, int is_helper) {
   p->name = strdup(name);
   p->stdout_file = stdout_file;
 
+  if (!is_helper)
+    return 0;
+
+  closefd(pipefd[1]);
+  unsetenv("UV_TEST_RUNNER_FD");
+
+  do
+    rc = read(pipefd[0], &n, 1);
+  while (rc == -1 && errno == EINTR);
+
+  closefd(pipefd[0]);
+
+  if (rc == -1) {
+    perror("read");
+    return -1;
+  }
+
+  if (rc > 0) {
+    fprintf(stderr, "EOF expected but got data.\n");
+    return -1;
+  }
+
   return 0;
 }
 
diff --git a/test/runner-win.c b/test/runner-win.c
index aa52d7cc..e3e91a7b 100644
--- a/test/runner-win.c
+++ b/test/runner-win.c
@@ -76,6 +76,11 @@ int process_start(char *name, char *part, process_info_t *p, int is_helper) {
   PROCESS_INFORMATION pi;
   DWORD result;
 
+  if (!is_helper) {
+    /* Give the helpers time to settle. Race-y, fix this. */
+    uv_sleep(250);
+  }
+
   if (GetTempPathW(sizeof(path) / sizeof(WCHAR), (WCHAR*)&path) == 0)
     goto error;
   if (GetTempFileNameW((WCHAR*)&path, L"uv", 0, (WCHAR*)&filename) == 0)
diff --git a/test/runner.c b/test/runner.c
index f017902a..aec560a5 100644
--- a/test/runner.c
+++ b/test/runner.c
@@ -215,9 +215,6 @@ int run_test(const char* test,
     process_count++;
   }
 
-  /* Give the helpers time to settle. Race-y, fix this. */
-  uv_sleep(250);
-
   /* Now start the test itself. */
   for (task = TASKS; task->main; task++) {
     if (strcmp(test, task->task_name) != 0) {
diff --git a/test/task.h b/test/task.h
index 92a90a54..282c02d5 100644
--- a/test/task.h
+++ b/test/task.h
@@ -181,6 +181,12 @@ extern int snprintf(char*, size_t, const char*, ...);
 # define UNUSED
 #endif
 
+#if defined(_WIN32)
+#define notify_parent_process() ((void) 0)
+#else
+extern void notify_parent_process(void);
+#endif
+
 /* Fully close a loop */
 static void close_walk_cb(uv_handle_t* handle, void* arg) {
   if (!uv_is_closing(handle))
diff --git a/test/test-ipc-heavy-traffic-deadlock-bug.c b/test/test-ipc-heavy-traffic-deadlock-bug.c
index 240fc645..325305a6 100644
--- a/test/test-ipc-heavy-traffic-deadlock-bug.c
+++ b/test/test-ipc-heavy-traffic-deadlock-bug.c
@@ -150,6 +150,7 @@ int ipc_helper_heavy_traffic_deadlock_bug(void) {
   r = uv_pipe_open(&pipe, 0);
   ASSERT(r == 0);
 
+  notify_parent_process();
   do_writes_and_reads((uv_stream_t*) &pipe);
   uv_sleep(100);
 
diff --git a/test/test-ipc-send-recv.c b/test/test-ipc-send-recv.c
index 3dedc86b..166225c0 100644
--- a/test/test-ipc-send-recv.c
+++ b/test/test-ipc-send-recv.c
@@ -397,6 +397,7 @@ int run_ipc_send_recv_helper(uv_loop_t* loop, int inprocess) {
     send_recv_start();
   }
 
+  notify_parent_process();
   r = uv_run(loop, UV_RUN_DEFAULT);
   ASSERT(r == 0);
 
diff --git a/test/test-ipc.c b/test/test-ipc.c
index 200f68d6..829d178d 100644
--- a/test/test-ipc.c
+++ b/test/test-ipc.c
@@ -724,6 +724,7 @@ int ipc_helper(int listen_after_write) {
     ASSERT(r == 0);
   }
 
+  notify_parent_process();
   r = uv_run(uv_default_loop(), UV_RUN_DEFAULT);
   ASSERT(r == 0);
 
diff --git a/test/test-stdio-over-pipes.c b/test/test-stdio-over-pipes.c
index 15744761..a130ff6a 100644
--- a/test/test-stdio-over-pipes.c
+++ b/test/test-stdio-over-pipes.c
@@ -232,6 +232,7 @@ int stdio_over_pipes_helper(void) {
     ASSERT(r == 0);
   }
 
+  notify_parent_process();
   uv_run(loop, UV_RUN_DEFAULT);
 
   ASSERT(after_write_called == 7);