For some reason arc4random_addrandom isn't present in 64-bit android archs. !

diff --git a/configure.ac b/configure.ac
index d42edd8..c511be7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -290,7 +290,7 @@ AC_HEADER_TIME
 
 dnl Checks for library functions.
 AC_CHECK_FUNCS([gettimeofday vasprintf fcntl clock_gettime strtok_r strsep])
-AC_CHECK_FUNCS([getnameinfo strlcpy inet_ntop inet_pton signal sigaction strtoll inet_aton pipe eventfd sendfile mmap splice arc4random arc4random_buf issetugid geteuid getegid getprotobynumber setenv unsetenv putenv sysctl])
+AC_CHECK_FUNCS([getnameinfo strlcpy inet_ntop inet_pton signal sigaction strtoll inet_aton pipe eventfd sendfile mmap splice arc4random arc4random_buf arc4random_addrandom issetugid geteuid getegid getprotobynumber setenv unsetenv putenv sysctl])
 AC_CHECK_FUNCS([umask])
 
 AC_CACHE_CHECK(
diff --git a/evutil_rand.c b/evutil_rand.c
index 284341c..97161e4 100644
--- a/evutil_rand.c
+++ b/evutil_rand.c
@@ -174,7 +174,9 @@ evutil_secure_rng_get_bytes(void *buf, size_t n)
 void
 evutil_secure_rng_add_bytes(const char *buf, size_t n)
 {
+#ifdef _EVENT_HAVE_ARC4RANDOM_ADDRANDOM
 	arc4random_addrandom((unsigned char*)buf,
 	    n>(size_t)INT_MAX ? INT_MAX : (int)n);
+#endif
 }