diff --git a/servers/slapd/proto-slap.h b/servers/slapd/proto-slap.h
index 1876c11426..a6d120ea25 100644
--- a/servers/slapd/proto-slap.h
+++ b/servers/slapd/proto-slap.h
@@ -777,8 +777,8 @@ LDAP_SLAPD_F (int)	krbv4_ldap_auth();
 /*
  * Other...
  */
-#define SLAP_SB_MAX_INCOMING_DEFAULT (1<<18 - 1)
-#define SLAP_SB_MAX_INCOMING_AUTH (1<<24 - 1)
+#define SLAP_SB_MAX_INCOMING_DEFAULT ((1<<18) - 1)
+#define SLAP_SB_MAX_INCOMING_AUTH ((1<<24) - 1)
 
 LDAP_SLAPD_F (ber_len_t) sockbuf_max_incoming;
 LDAP_SLAPD_F (ber_len_t) sockbuf_max_incoming_auth;