-/* Returns the number of milliseconds from boot time: this should be monotonic */
-guint32 mono_msec_ticks (void) MONO_INTERNAL;
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+
+/* Returns the number of milliseconds from boot time: this should be monotonic
+ *
+ * Prefer to use mono_msec_ticks for elapsed time calculation. */
+gint64 mono_msec_boottime (void);
+
+/* Returns the number of milliseconds ticks from unspecified time: this should be monotonic */
+gint64 mono_msec_ticks (void);