diff --git a/lib/libcasper/services/cap_grp/cap_grp.h b/lib/libcasper/services/cap_grp/cap_grp.h
index 84b9c7bab034..7c109bcc199c 100644
--- a/lib/libcasper/services/cap_grp/cap_grp.h
+++ b/lib/libcasper/services/cap_grp/cap_grp.h
@@ -65,7 +65,7 @@ int cap_grp_limit_groups(cap_channel_t *chan, const char * const *names,
 
 #define	cap_setgroupent(chan, stayopen) etgroupent(stayopen)
 #define endgrent(chan)			endgrent()
-inline int
+static inline int
 cap_setgrent(cap_channel_t *chan __unused)
 {