diff --git a/rcl/test/CMakeLists.txt b/rcl/test/CMakeLists.txt
index 59c88d7..f090b36 100644
--- a/rcl/test/CMakeLists.txt
+++ b/rcl/test/CMakeLists.txt
@@ -204,3 +204,10 @@ rcl_add_custom_gtest(test_expand_topic_name
   APPEND_LIBRARY_DIRS ${extra_lib_dirs}
   LIBRARIES ${PROJECT_NAME} ${extra_test_libraries}
 )
+
+rcl_add_custom_gtest(test_timer${target_suffix}
+  SRCS rcl/test_timer.cpp
+  ENV ${extra_test_env}
+  APPEND_LIBRARY_DIRS ${extra_lib_dirs}
+  LIBRARIES ${PROJECT_NAME} ${extra_test_libraries}
+)
diff --git a/rcl/test/rcl/test_timer.cpp b/rcl/test/rcl/test_timer.cpp
new file mode 100644
index 0000000..571e3f9
--- /dev/null
+++ b/rcl/test/rcl/test_timer.cpp
@@ -0,0 +1,234 @@
+// Copyright 2017 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <gtest/gtest.h>
+
+#include "rcl/timer.h"
+
+#include "rcl/rcl.h"
+
+#include "../memory_tools/memory_tools.hpp"
+#include "../scope_exit.hpp"
+#include "rcl/error_handling.h"
+
+
+class TestTimerFixture : public ::testing::Test
+{
+public:
+  rcl_node_t * node_ptr;
+  void SetUp()
+  {
+    stop_memory_checking();
+    rcl_ret_t ret;
+    ret = rcl_init(0, nullptr, rcl_get_default_allocator());
+    ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+    this->node_ptr = new rcl_node_t;
+    *this->node_ptr = rcl_get_zero_initialized_node();
+    const char * name = "test_publisher_node";
+    rcl_node_options_t node_options = rcl_node_get_default_options();
+    ret = rcl_node_init(this->node_ptr, name, "", &node_options);
+    ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+    set_on_unexpected_malloc_callback([]() {ASSERT_FALSE(true) << "UNEXPECTED MALLOC";});
+    set_on_unexpected_realloc_callback([]() {ASSERT_FALSE(true) << "UNEXPECTED REALLOC";});
+    set_on_unexpected_free_callback([]() {ASSERT_FALSE(true) << "UNEXPECTED FREE";});
+    start_memory_checking();
+  }
+
+  void TearDown()
+  {
+    assert_no_malloc_end();
+    assert_no_realloc_end();
+    assert_no_free_end();
+    stop_memory_checking();
+    set_on_unexpected_malloc_callback(nullptr);
+    set_on_unexpected_realloc_callback(nullptr);
+    set_on_unexpected_free_callback(nullptr);
+    rcl_ret_t ret = rcl_node_fini(this->node_ptr);
+    delete this->node_ptr;
+    EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+    ret = rcl_shutdown();
+    EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+  }
+};
+
+TEST_F(TestTimerFixture, test_two_timers) {
+  stop_memory_checking();
+  rcl_ret_t ret;
+  rcl_timer_t timer = rcl_get_zero_initialized_timer();
+  rcl_timer_t timer2 = rcl_get_zero_initialized_timer();
+
+  ret = rcl_timer_init(&timer, RCL_MS_TO_NS(5), nullptr, rcl_get_default_allocator());
+  ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+
+  ret = rcl_timer_init(&timer2, RCL_MS_TO_NS(20), nullptr, rcl_get_default_allocator());
+  ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+
+  rcl_wait_set_t wait_set = rcl_get_zero_initialized_wait_set();
+  ret = rcl_wait_set_init(&wait_set, 0, 0, 2, 0, 0, rcl_get_default_allocator());
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+
+  ret = rcl_wait_set_add_timer(&wait_set, &timer);
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+  ret = rcl_wait_set_add_timer(&wait_set, &timer2);
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+  auto timer_exit = make_scope_exit([&timer, &timer2, &wait_set]() {
+        stop_memory_checking();
+        rcl_ret_t ret = rcl_timer_fini(&timer);
+        EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+        ret = rcl_timer_fini(&timer2);
+        EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+        ret = rcl_wait_set_fini(&wait_set);
+        EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+      });
+  ret = rcl_wait(&wait_set, RCL_MS_TO_NS(10));
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+  uint8_t nonnull_timers = 0;
+  for (uint8_t i = 0; i < wait_set.size_of_timers; i++) {
+    if (wait_set.timers[i] != NULL) {
+      nonnull_timers++;
+    }
+  }
+  bool is_ready = false;
+  ret = rcl_timer_is_ready(&timer, &is_ready);
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+  EXPECT_TRUE(is_ready);
+  ret = rcl_timer_is_ready(&timer2, &is_ready);
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+  EXPECT_FALSE(is_ready);
+  ASSERT_EQ(1, nonnull_timers);
+}
+
+TEST_F(TestTimerFixture, test_two_timers_ready_before_timeout) {
+  stop_memory_checking();
+  rcl_ret_t ret;
+  rcl_timer_t timer = rcl_get_zero_initialized_timer();
+  rcl_timer_t timer2 = rcl_get_zero_initialized_timer();
+
+  ret = rcl_timer_init(&timer, RCL_MS_TO_NS(5), nullptr, rcl_get_default_allocator());
+  ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+
+  ret = rcl_timer_init(&timer2, RCL_MS_TO_NS(10), nullptr, rcl_get_default_allocator());
+  ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+
+  rcl_wait_set_t wait_set = rcl_get_zero_initialized_wait_set();
+  ret = rcl_wait_set_init(&wait_set, 0, 0, 2, 0, 0, rcl_get_default_allocator());
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+
+  ret = rcl_wait_set_add_timer(&wait_set, &timer);
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+  ret = rcl_wait_set_add_timer(&wait_set, &timer2);
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+  auto timer_exit = make_scope_exit([&timer, &timer2, &wait_set]() {
+        stop_memory_checking();
+        rcl_ret_t ret = rcl_timer_fini(&timer);
+        EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+        ret = rcl_timer_fini(&timer2);
+        EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+        ret = rcl_wait_set_fini(&wait_set);
+        EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+      });
+  ret = rcl_wait(&wait_set, RCL_MS_TO_NS(20));
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+  uint8_t nonnull_timers = 0;
+  for (uint8_t i = 0; i < wait_set.size_of_timers; i++) {
+    if (wait_set.timers[i] != NULL) {
+      nonnull_timers++;
+    }
+  }
+  bool is_ready = false;
+  ret = rcl_timer_is_ready(&timer, &is_ready);
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+  EXPECT_TRUE(is_ready);
+  ret = rcl_timer_is_ready(&timer2, &is_ready);
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+  EXPECT_FALSE(is_ready);
+  ASSERT_EQ(1, nonnull_timers);
+}
+
+TEST_F(TestTimerFixture, test_timer_not_ready) {
+  stop_memory_checking();
+  rcl_ret_t ret;
+  rcl_timer_t timer = rcl_get_zero_initialized_timer();
+
+  ret = rcl_timer_init(&timer, RCL_MS_TO_NS(5), nullptr, rcl_get_default_allocator());
+  ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+
+  rcl_wait_set_t wait_set = rcl_get_zero_initialized_wait_set();
+  ret = rcl_wait_set_init(&wait_set, 0, 0, 1, 0, 0, rcl_get_default_allocator());
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+
+  ret = rcl_wait_set_add_timer(&wait_set, &timer);
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+
+  auto timer_exit = make_scope_exit([&timer, &wait_set]() {
+        stop_memory_checking();
+        rcl_ret_t ret = rcl_timer_fini(&timer);
+        EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+        ret = rcl_wait_set_fini(&wait_set);
+        EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+      });
+  ret = rcl_wait(&wait_set, RCL_MS_TO_NS(1));
+  EXPECT_EQ(RCL_RET_TIMEOUT, ret) << rcl_get_error_string_safe();
+  uint8_t nonnull_timers = 0;
+  for (uint8_t i = 0; i < wait_set.size_of_timers; i++) {
+    if (wait_set.timers[i] != NULL) {
+      nonnull_timers++;
+    }
+  }
+  bool is_ready = false;
+  ret = rcl_timer_is_ready(&timer, &is_ready);
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+  EXPECT_FALSE(is_ready);
+  ASSERT_EQ(0, nonnull_timers);
+}
+
+TEST_F(TestTimerFixture, test_canceled_timer) {
+  stop_memory_checking();
+  rcl_ret_t ret;
+  rcl_timer_t timer = rcl_get_zero_initialized_timer();
+
+  ret = rcl_timer_init(&timer, 500, nullptr, rcl_get_default_allocator());
+  ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+
+  ret = rcl_timer_cancel(&timer);
+  ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+
+  rcl_wait_set_t wait_set = rcl_get_zero_initialized_wait_set();
+  ret = rcl_wait_set_init(&wait_set, 0, 0, 1, 0, 0, rcl_get_default_allocator());
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+
+  ret = rcl_wait_set_add_timer(&wait_set, &timer);
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+
+  auto timer_exit = make_scope_exit([&timer, &wait_set]() {
+        stop_memory_checking();
+        rcl_ret_t ret = rcl_timer_fini(&timer);
+        EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+        ret = rcl_wait_set_fini(&wait_set);
+        EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+      });
+  ret = rcl_wait(&wait_set, RCL_MS_TO_NS(1));
+  EXPECT_EQ(RCL_RET_TIMEOUT, ret) << rcl_get_error_string_safe();
+  uint8_t nonnull_timers = 0;
+  for (uint8_t i = 0; i < wait_set.size_of_timers; i++) {
+    if (wait_set.timers[i] != NULL) {
+      nonnull_timers++;
+    }
+  }
+  bool is_ready = false;
+  ret = rcl_timer_is_ready(&timer, &is_ready);
+  EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
+  EXPECT_FALSE(is_ready);
+  ASSERT_EQ(0, nonnull_timers);
+}