diff --git a/tests/signal_test.cpp b/tests/signal_test.cpp
index 8fd8b72..f8fdc3f 100644
--- a/tests/signal_test.cpp
+++ b/tests/signal_test.cpp
@@ -16,9 +16,10 @@
 
 #include <signal.h>
 
-#include <errno.h>
 #include <gtest/gtest.h>
 
+#include <errno.h>
+
 #include "ScopedSignalHandler.h"
 
 static size_t SIGNAL_MIN() {
@@ -276,3 +277,101 @@
   // We don't currently reserve any at the top.
   ASSERT_EQ(SIGRTMAX, __SIGRTMAX);
 }
+
+static int g_sigqueue_signal_handler_call_count = 0;
+
+static void SigqueueSignalHandler(int signum, siginfo_t* info, void*) {
+  ASSERT_EQ(SIGALRM, signum);
+  ASSERT_EQ(SIGALRM, info->si_signo);
+  ASSERT_EQ(SI_QUEUE, info->si_code);
+  ASSERT_EQ(1, info->si_value.sival_int);
+  ++g_sigqueue_signal_handler_call_count;
+}
+
+TEST(signal, sigqueue) {
+  ScopedSignalHandler ssh(SIGALRM, SigqueueSignalHandler, SA_SIGINFO);
+  sigval_t sigval;
+  sigval.sival_int = 1;
+  errno = 0;
+  ASSERT_EQ(0, sigqueue(getpid(), SIGALRM, sigval));
+  ASSERT_EQ(0, errno);
+  ASSERT_EQ(1, g_sigqueue_signal_handler_call_count);
+}
+
+TEST(signal, sigwaitinfo) {
+  // Block SIGALRM.
+  sigset_t just_SIGALRM;
+  sigemptyset(&just_SIGALRM);
+  sigaddset(&just_SIGALRM, SIGALRM);
+  sigset_t original_set;
+  ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &just_SIGALRM, &original_set));
+
+  // Raise SIGALRM.
+  sigval_t sigval;
+  sigval.sival_int = 1;
+  ASSERT_EQ(0, sigqueue(getpid(), SIGALRM, sigval));
+
+  // Get pending SIGALRM.
+  siginfo_t info;
+  errno = 0;
+  ASSERT_EQ(SIGALRM, sigwaitinfo(&just_SIGALRM, &info));
+  ASSERT_EQ(0, errno);
+  ASSERT_EQ(SIGALRM, info.si_signo);
+  ASSERT_EQ(1, info.si_value.sival_int);
+
+  ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &original_set, NULL));
+}
+
+TEST(signal, sigtimedwait) {
+  // Block SIGALRM.
+  sigset_t just_SIGALRM;
+  sigemptyset(&just_SIGALRM);
+  sigaddset(&just_SIGALRM, SIGALRM);
+  sigset_t original_set;
+  ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &just_SIGALRM, &original_set));
+
+  // Raise SIGALRM.
+  sigval_t sigval;
+  sigval.sival_int = 1;
+  ASSERT_EQ(0, sigqueue(getpid(), SIGALRM, sigval));
+
+  // Get pending SIGALRM.
+  siginfo_t info;
+  struct timespec timeout;
+  timeout.tv_sec = 2;
+  timeout.tv_nsec = 0;
+  errno = 0;
+  ASSERT_EQ(SIGALRM, sigtimedwait(&just_SIGALRM, &info, &timeout));
+  ASSERT_EQ(0, errno);
+
+  ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &original_set, NULL));
+}
+
+static int64_t NanoTime() {
+  struct timespec t;
+  t.tv_sec = t.tv_nsec = 0;
+  clock_gettime(CLOCK_MONOTONIC, &t);
+  return static_cast<int64_t>(t.tv_sec) * 1000000000LL + t.tv_nsec;
+}
+
+TEST(signal, sigtimedwait_timeout) {
+  // Block SIGALRM.
+  sigset_t just_SIGALRM;
+  sigemptyset(&just_SIGALRM);
+  sigaddset(&just_SIGALRM, SIGALRM);
+  sigset_t original_set;
+  ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &just_SIGALRM, &original_set));
+
+  // Wait timeout.
+  int64_t start_time = NanoTime();
+  siginfo_t info;
+  struct timespec timeout;
+  timeout.tv_sec = 0;
+  timeout.tv_nsec = 1000000;
+  errno = 0;
+  ASSERT_EQ(-1, sigtimedwait(&just_SIGALRM, &info, &timeout));
+  ASSERT_EQ(EAGAIN, errno);
+  ASSERT_GE(NanoTime() - start_time, 1000000);
+
+  ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &original_set, NULL));
+}