diff --git a/Makefile.am b/Makefile.am
index 5e985bd..bdebce2 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -2,7 +2,7 @@ ACLOCAL_AMFLAGS     = -I m4
 
 lib_LTLIBRARIES     = libuev.la
 libuev_la_SOURCES   = uev.c io.c timer.c signal.c cron.c
-libuev_la_CPPFLAGS  = -D_GNU_SOURCE
+libuev_la_CPPFLAGS  = -D_GNU_SOURCE -D_TIME_BITS=64
 libuev_la_CFLAGS    = -W -Wall -Wextra
 libuev_la_LDFLAGS   = $(AM_LDFLAGS) -version-info 1:2:0