diff --git a/include/polarssl/oid.h b/include/polarssl/oid.h
index 6b04893..31a7d2b 100644
--- a/include/polarssl/oid.h
+++ b/include/polarssl/oid.h
@@ -122,6 +122,7 @@
 #define OID_AT_GIVEN_NAME               OID_AT "\x2A" /**< id-at-givenName AttributeType:= {id-at 42} */
 #define OID_AT_INITIALS                 OID_AT "\x2B" /**< id-at-initials AttributeType:= {id-at 43} */
 #define OID_AT_GENERATION_QUALIFIER     OID_AT "\x2C" /**< id-at-generationQualifier AttributeType:= {id-at 44} */
+#define OID_AT_UNIQUE_IDENTIFIER        OID_AT "\x2D" /**< id-at-uniqueIdentifier AttributType:= {id-at 45} */
 #define OID_AT_DN_QUALIFIER             OID_AT "\x2E" /**< id-at-dnQualifier AttributeType:= {id-at 46} */
 #define OID_AT_PSEUDONYM                OID_AT "\x41" /**< id-at-pseudonym AttributeType:= {id-at 65} */