diff --git a/panel-plugin/libacpi.c b/panel-plugin/libacpi.c
index 141ee23..015d6a5 100644
--- a/panel-plugin/libacpi.c
+++ b/panel-plugin/libacpi.c
@@ -63,7 +63,12 @@ static char sysfsacdir[280];
 
 #ifndef __linux__
 #if HAVE_SYSCTL
- static int
+
+#include <sys/sysctl.h>
+#include <err.h>
+#include <errno.h>
+
+static int
 name2oid(char *name, int *oidp)
 {
     int oid[2];