--- a/include/syslog.h
+++ b/include/syslog.h
@@ -21,7 +21,7 @@ extern "C" {
 #define	LOG_MAKEPRI(f, p) (((f)<<3)|(p))
 
 #define LOG_MASK(p) (1<<(p))
-#define LOG_UPTO(p) ((1<<(p)+1)-1)
+#define LOG_UPTO(p) ((1<<((p)+1))-1)
 
 #define LOG_KERN     (0<<3)
 #define LOG_USER     (1<<3)
