diff --git a/coreutils/id.c b/coreutils/id.c
index 4c524a225..6af677404 100644
--- a/coreutils/id.c
+++ b/coreutils/id.c
@@ -26,6 +26,7 @@
 #include <unistd.h>
 #include <pwd.h>
 #include <grp.h>
+#include <getopt.h>
 #include <sys/types.h>
 
 extern int id_main(int argc, char **argv)
diff --git a/id.c b/id.c
index 4c524a225..6af677404 100644
--- a/id.c
+++ b/id.c
@@ -26,6 +26,7 @@
 #include <unistd.h>
 #include <pwd.h>
 #include <grp.h>
+#include <getopt.h>
 #include <sys/types.h>
 
 extern int id_main(int argc, char **argv)