initgroups needs grp.h
diff --git a/misc.c b/misc.c
index d94438d..0134d69 100644
--- a/misc.c
+++ b/misc.c
@@ -56,6 +56,7 @@
 #ifdef HAVE_PATHS_H
 # include <paths.h>
 #include <pwd.h>
+#include <grp.h>
 #endif
 #ifdef SSH_TUN_OPENBSD
 #include <net/if.h>