diff --git a/gmid.c b/gmid.c
index 4908c7b..8f73566 100644
--- a/gmid.c
+++ b/gmid.c
@@ -23,6 +23,7 @@
 #include <getopt.h>
 #include <libgen.h>
 #include <limits.h>
+#include <grp.h>
 #include <pwd.h>
 #include <signal.h>
 #include <string.h>