diff --git a/tests/headers/posix/signal_h.c b/tests/headers/posix/signal_h.c
index c2e544e..82751f4 100644
--- a/tests/headers/posix/signal_h.c
+++ b/tests/headers/posix/signal_h.c
@@ -63,6 +63,10 @@
   MACRO(SIGEV_SIGNAL);
   MACRO(SIGEV_THREAD);
 
+#if !defined(__GLIBC__)  // Our glibc is too old.
+  MACRO(SIG2STR_MAX);
+#endif
+
   TYPE(union sigval);
   STRUCT_MEMBER(union sigval, int, sival_int);
   STRUCT_MEMBER(union sigval, void*, sival_ptr);
@@ -205,6 +209,9 @@
   FUNCTION(pthread_kill, int (*f)(pthread_t, int));
   FUNCTION(pthread_sigmask, int (*f)(int, const sigset_t*, sigset_t*));
   FUNCTION(raise, int (*f)(int));
+#if !defined(__GLIBC__)  // Our glibc is too old.
+  FUNCTION(sig2str, int (*f)(int, char*));
+#endif
   FUNCTION(sigaction, int (*f)(int, const struct sigaction*, struct sigaction*));
   FUNCTION(sigaddset, int (*f)(sigset_t*, int));
   FUNCTION(sigaltstack, int (*f)(const stack_t*, stack_t*));
@@ -226,4 +233,7 @@
   FUNCTION(sigtimedwait, int (*f)(const sigset_t*, siginfo_t*, const struct timespec*));
   FUNCTION(sigwait, int (*f)(const sigset_t*, int*));
   FUNCTION(sigwaitinfo, int (*f)(const sigset_t*, siginfo_t*));
+#if !defined(__GLIBC__)  // Our glibc is too old.
+  FUNCTION(str2sig, int (*f)(const char*, int*));
+#endif
 }
diff --git a/tests/signal_test.cpp b/tests/signal_test.cpp
index de126da..c1719dc 100644
--- a/tests/signal_test.cpp
+++ b/tests/signal_test.cpp
@@ -982,3 +982,94 @@
   ASSERT_EQ(-1, killpg(-1, SIGKILL));
   ASSERT_ERRNO(EINVAL);
 }
+
+TEST(signal, sig2str) {
+#if defined(__BIONIC__)
+  char str[SIG2STR_MAX];
+
+  // A regular signal.
+  ASSERT_EQ(0, sig2str(SIGHUP, str));
+  ASSERT_STREQ("HUP", str);
+
+  // A real-time signal.
+  ASSERT_EQ(0, sig2str(SIGRTMIN + 4, str));
+  ASSERT_STREQ("RTMIN+4", str);
+  ASSERT_EQ(0, sig2str(SIGRTMAX - 4, str));
+  ASSERT_STREQ("RTMAX-4", str);
+  // Special cases.
+  ASSERT_EQ(0, sig2str(SIGRTMAX, str));
+  ASSERT_STREQ("RTMAX", str);
+  ASSERT_EQ(0, sig2str(SIGRTMIN, str));
+  ASSERT_STREQ("RTMIN", str);
+  // One of the signals the C library keeps to itself.
+  ASSERT_EQ(-1, sig2str(32, str));  // __SIGRTMIN
+
+  // Errors.
+  ASSERT_EQ(-1, sig2str(-1, str));    // Too small.
+  ASSERT_EQ(-1, sig2str(0, str));     // Still too small.
+  ASSERT_EQ(-1, sig2str(1234, str));  // Too large.
+#else
+  GTEST_SKIP() << "our old glibc doesn't have sig2str";
+#endif
+}
+
+TEST(signal, str2sig) {
+#if defined(__BIONIC__)
+  int sig;
+
+  // A regular signal, by number.
+  sig = -1;
+  ASSERT_EQ(0, str2sig("9", &sig));
+  ASSERT_EQ(SIGKILL, sig);
+
+  // A regular signal, by name.
+  sig = -1;
+  ASSERT_EQ(0, str2sig("HUP", &sig));
+  ASSERT_EQ(SIGHUP, sig);
+
+  // A real-time signal, by number.
+  sig = -1;
+  ASSERT_EQ(0, str2sig("64", &sig));
+  ASSERT_EQ(SIGRTMAX, sig);
+
+  // A real-time signal, by name and offset.
+  sig = -1;
+  ASSERT_EQ(0, str2sig("RTMAX-4", &sig));
+  ASSERT_EQ(SIGRTMAX - 4, sig);
+  sig = -1;
+  ASSERT_EQ(0, str2sig("RTMIN+4", &sig));
+  ASSERT_EQ(SIGRTMIN + 4, sig);
+  // Unspecified by POSIX, but we try to be reasonable.
+  sig = -1;
+  ASSERT_EQ(0, str2sig("RTMAX-0", &sig));
+  ASSERT_EQ(SIGRTMAX, sig);
+  sig = -1;
+  ASSERT_EQ(0, str2sig("RTMIN+0", &sig));
+  ASSERT_EQ(SIGRTMIN, sig);
+  // One of the signals the C library keeps to itself, numerically.
+  ASSERT_EQ(-1, str2sig("32", &sig));  // __SIGRTMIN
+
+  // Special cases.
+  sig = -1;
+  ASSERT_EQ(0, str2sig("RTMAX", &sig));
+  ASSERT_EQ(SIGRTMAX, sig);
+  sig = -1;
+  ASSERT_EQ(0, str2sig("RTMIN", &sig));
+  ASSERT_EQ(SIGRTMIN, sig);
+
+  // Errors.
+  ASSERT_EQ(-1, str2sig("SIGHUP", &sig));     // No "SIG" prefix allowed.
+  ASSERT_EQ(-1, str2sig("-1", &sig));         // Too small.
+  ASSERT_EQ(-1, str2sig("0", &sig));          // Still too small.
+  ASSERT_EQ(-1, str2sig("1234", &sig));       // Too large.
+  ASSERT_EQ(-1, str2sig("RTMAX-666", &sig));  // Offset too small.
+  ASSERT_EQ(-1, str2sig("RTMIN+666", &sig));  // Offset too large.
+  ASSERT_EQ(-1, str2sig("RTMAX-+1", &sig));   // Silly.
+  ASSERT_EQ(-1, str2sig("RTMIN+-1", &sig));   // Silly.
+  ASSERT_EQ(-1, str2sig("HUPs", &sig));       // Trailing junk.
+  ASSERT_EQ(-1, str2sig("2b", &sig));         // Trailing junk.
+  ASSERT_EQ(-1, str2sig("RTMIN+2b", &sig));   // Trailing junk.
+#else
+  GTEST_SKIP() << "our old glibc doesn't have str2sig";
+#endif
+}