diff --git a/include/ldap.h b/include/ldap.h
index 907f8c4a1d3c41f178c2f507ff6f6e8afeb96207..7c421c3360c06b9efaa1800ae2399f244616145d 100644
--- a/include/ldap.h
+++ b/include/ldap.h
@@ -205,6 +205,13 @@ typedef struct ldapcontrol {
 
 #define LDAP_EXOP_X_WHO_AM_I	"1.3.6.1.4.1.4203.1.11.3"
 
+/* LDAP Features */
+#define LDAP_FEATURE_ALL_OPERATIONAL_ATTRS "1.3.6.1.4.1.4203.1.5.1"  /* + */
+#define LDAP_FEATURE_OBJECTCLASS_ATTRS "1.3.6.1.4.1.4203.1.5.2"
+#define LDAP_FEATURE_ABSOLUTE_FILTERS "1.3.6.1.4.1.4203.1.5.3"  /* (&) (|) */
+#define LDAP_FEATURE_LANGUAGE_TAG_OPTIONS "1.3.6.1.4.1.4203.1.5.4"
+#define LDAP_FEATURE_LANGUAGE_RANGE_OPTIONS "1.3.6.1.4.1.4203.1.5.5"
+
 /*
  * specific LDAP instantiations of BER types we know about
  */