diff --git a/src/cat.c b/src/cat.c
index 6b746ed..273ec9a 100644
--- a/src/cat.c
+++ b/src/cat.c
@@ -3,7 +3,6 @@
 
 
 #include <unistd.h>
-extern int optind;
 #include <stdio.h>
 #include <string.h>
 
diff --git a/src/cmp.c b/src/cmp.c
index a4d1343..20eba94 100644
--- a/src/cmp.c
+++ b/src/cmp.c
@@ -3,7 +3,6 @@
 
 
 #include <unistd.h>
-extern int optind;
 #include <stdio.h>
 #include <string.h>
 
diff --git a/src/cp.c b/src/cp.c
index 54c57db..b7e6ceb 100644
--- a/src/cp.c
+++ b/src/cp.c
@@ -5,7 +5,6 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
-extern int optind;
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
diff --git a/src/head.c b/src/head.c
index 0066d61..f3172af 100644
--- a/src/head.c
+++ b/src/head.c
@@ -3,8 +3,6 @@
 
 
 #include <unistd.h>
-extern int optind;
-extern char * optarg;
 #include <stdlib.h>
 #include <stdio.h>
 
diff --git a/src/id.c b/src/id.c
index 2253828..5f20f14 100644
--- a/src/id.c
+++ b/src/id.c
@@ -3,7 +3,6 @@
 
 
 #include <unistd.h>
-extern int optind;
 #include <pwd.h>
 #include <grp.h>
 #include <sys/types.h>
diff --git a/src/kill.c b/src/kill.c
index 17598d9..48484f8 100644
--- a/src/kill.c
+++ b/src/kill.c
@@ -5,8 +5,6 @@
 #include <sys/types.h>
 #include <signal.h>
 #include <unistd.h>
-extern char * optarg;
-extern int optind;
 #include <stdlib.h>
 #include <stdio.h>
 
diff --git a/src/ln.c b/src/ln.c
index aaef54c..15d1a98 100644
--- a/src/ln.c
+++ b/src/ln.c
@@ -5,7 +5,6 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
-extern int optind;
 #include <stdlib.h>
 #include <stdio.h>
 #include <errno.h>
diff --git a/src/mkfifo.c b/src/mkfifo.c
index 276d96a..ba64994 100644
--- a/src/mkfifo.c
+++ b/src/mkfifo.c
@@ -5,8 +5,6 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
-extern char * optarg;
-extern int optind;
 #include <stdio.h>
 #include <stdlib.h>
 
diff --git a/src/pwd.c b/src/pwd.c
index af6e2c6..eeca9e3 100644
--- a/src/pwd.c
+++ b/src/pwd.c
@@ -3,7 +3,6 @@
 
 
 #include <unistd.h>
-extern int optind;
 #include <stdlib.h>
 #include <stdio.h>
 
diff --git a/src/rmdir.c b/src/rmdir.c
index 495e94e..20f9f1e 100644
--- a/src/rmdir.c
+++ b/src/rmdir.c
@@ -3,7 +3,6 @@
 
 
 #include <unistd.h>
-extern int optind;
 #include <stdio.h>
 
 
diff --git a/src/strings.c b/src/strings.c
index 46ce9b4..829db73 100644
--- a/src/strings.c
+++ b/src/strings.c
@@ -3,8 +3,6 @@
 
 
 #include <unistd.h>
-extern int optind;
-extern char * optarg;
 #include <ctype.h>
 #include <stdlib.h>
 #include <stdio.h>
diff --git a/src/time.c b/src/time.c
index 862bab3..8b5a09b 100644
--- a/src/time.c
+++ b/src/time.c
@@ -6,7 +6,6 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
-extern int optind;
 #include <stdio.h>
 #include <errno.h>
 
diff --git a/src/wc.c b/src/wc.c
index 7a368db..e5f0a8b 100644
--- a/src/wc.c
+++ b/src/wc.c
@@ -3,7 +3,6 @@
 
 
 #include <unistd.h>
-extern int optind;
 #include <ctype.h>
 #include <stdio.h>