diff --git a/src/ecogrep.c b/src/ecogrep.c
index 8d45312..d9fe676 100644
--- a/src/ecogrep.c
+++ b/src/ecogrep.c
@@ -5,6 +5,7 @@
 #include <getopt.h>
 #include <stdlib.h>
 #include <sys/stat.h>
+#include <unistd.h>
 
 
 #define VERSION "0.1"