diff --git a/lib/libcasper/libcasper/libcasper.h b/lib/libcasper/libcasper/libcasper.h
index c8ed184d92cd..b55619b01506 100644
--- a/lib/libcasper/libcasper/libcasper.h
+++ b/lib/libcasper/libcasper/libcasper.h
@@ -123,8 +123,21 @@ cap_channel_t	*cap_service_open(const cap_channel_t *chan, const char *name);
 int		 cap_service_limit(const cap_channel_t *chan,
 		    const char * const *names, size_t nnames);
 #else
-#define	cap_service_open(chan, name)		(cap_init())
-#define	cap_service_limit(chan, names, nnames)	(0)
+static inline cap_channel_t *
+cap_service_open(const cap_channel_t *chan __unused,
+    const char *name __unused)
+{
+
+	return (cap_init());
+}
+
+static inline int
+cap_service_limit(const cap_channel_t *chan __unused,
+    const char * const *names __unused, size_t nnames __unused)
+{
+
+	return (0);
+}
 #endif
 
 /*
@@ -229,7 +242,13 @@ int	cap_sock(const cap_channel_t *chan);
 #ifdef WITH_CASPER
 int	cap_limit_set(const cap_channel_t *chan, nvlist_t *limits);
 #else
-#define	cap_limit_set(chan, limits)	(0)
+static inline int
+cap_limit_set(const cap_channel_t *chan __unused,
+    nvlist_t *limits __unused)
+{
+
+	return (0);
+}
 #endif
 
 /*