-CPPFLAGS += -std=c99 -D_GNU_SOURCE=1
-CFLAGS += -Wall -Wsign-compare -Wpointer-arith -Wcast-qual -Wcast-align
+CPPFLAGS += -D_GNU_SOURCE=1
+CFLAGS += -std=c99 -Wall -Wsign-compare -Wpointer-arith -Wcast-qual \
+ -Wcast-align -D_GNU_SOURCE=1 -D_FILE_OFFSET_BITS=64