diff --git a/Makefile b/Makefile
index a0968af..46d10f8 100644
--- a/Makefile
+++ b/Makefile
@@ -18,7 +18,7 @@ VERSION-FILE: FORCE
 	@$(SHELL_PATH) ./GEN-VERSION-FILE
 -include VERSION-FILE
 
-CFLAGS = -g -O2 -Wall -W -Werror=format-security
+CFLAGS = -g -O2 -Wall -W -Werror=format-security -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
 LDFLAGS =
 IPTRAF_CFLAGS := -std=gnu99 -D_GNU_SOURCE
 ALL_CFLAGS = $(CPPFLAGS) $(CFLAGS) $(IPTRAF_CFLAGS)