diff --git a/library/platform_util.c b/library/platform_util.c
index 6d2dd14..cc46340 100644
--- a/library/platform_util.c
+++ b/library/platform_util.c
@@ -243,10 +243,10 @@
 #include <time.h>
 #if !defined(_WIN32) && \
     (defined(unix) || defined(__unix) || defined(__unix__) || \
-    (defined(__APPLE__) && defined(__MACH__)))
+    (defined(__APPLE__) && defined(__MACH__)) || defined(__HAIKU__))
 #include <unistd.h>
-#endif /* !_WIN32 && (unix || __unix || __unix__ || (__APPLE__ && __MACH__)) */
-#if (defined(_POSIX_VERSION) && _POSIX_VERSION >= 199309L)
+#endif /* !_WIN32 && (unix || __unix || __unix__ || (__APPLE__ && __MACH__) || defined(__HAIKU__)) */
+#if (defined(_POSIX_VERSION) && _POSIX_VERSION >= 199309L) || defined(__HAIKU__)
 mbedtls_ms_time_t mbedtls_ms_time(void)
 {
     int ret;