diff --git a/scheme/ldap-constants.scm b/scheme/ldap-constants.scm
index 7c01aea..9b74a41 100644
--- a/scheme/ldap-constants.scm
+++ b/scheme/ldap-constants.scm
@@ -102,12 +102,26 @@
        (make-string-constant 
 	"LDAP_ALL_USER_ATTRIBUTES" "ldap-attributes-all-user-attributes")))
 
+    (define ldap-message-types
+      (map make-constant-from-c-name-integer
+	   '("LDAP_RES_BIND"
+	     "LDAP_RES_SEARCH_ENTRY"
+	     "LDAP_RES_SEARCH_REFERENCE"
+	     "LDAP_RES_SEARCH_RESULT"
+	     "LDAP_RES_MODIFY"
+	     "LDAP_RES_ADD"
+	     "LDAP_RES_DELETE"
+	     "LDAP_RES_MODDN"
+	     "LDAP_RES_COMPARE"
+	     "LDAP_RES_EXTENDED")))
+
     (define ldap-all-constants
       (append ldap-return-codes
 	      ldap-opt-protocol-version
 	      ldap-scope-arguments
 	      ldap-attribute-selectors
-	      ldap-session-options))
+	      ldap-session-options
+	      ldap-message-types))
 	   
     (define (write-source-file name string)
       (call-with-output-file name
@@ -153,6 +167,10 @@
 	 "ldap-session-options" (make-drop-common-prefix-name-converter "LDAP_OPT_")
 	 ldap-session-options)
 
+	(generate-finite-type-definition
+	 "ldap-message-types" (make-drop-common-prefix-name-converter "LDAP_RES_")
+	 ldap-message-types)
+
 	(string-join
 	 (map generate-binding ldap-attribute-selectors)))))