diff --git a/scheme/ldap-constants.scm b/scheme/ldap-constants.scm
index 1dba403..7c01aea 100644
--- a/scheme/ldap-constants.scm
+++ b/scheme/ldap-constants.scm
@@ -5,7 +5,7 @@
 
 (define-structure ldap-constants ldap-constants-interface
   (open
-   scheme signals
+   scheme signals srfi-13
    ffi-import-constants)
   (begin
 
@@ -74,9 +74,40 @@
       (map make-constant-from-c-name-integer
 	   '("LDAP_VERSION" "LDAP_VERSION3")))
 
+    (define ldap-scope-arguments
+      (map make-constant-from-c-name-integer
+	   '("LDAP_SCOPE_BASE" "LDAP_SCOPE_ONELEVEL" "LDAP_SCOPE_SUBTREE")))
+
+    (define ldap-session-options
+      (map make-constant-from-c-name-integer
+	   '("LDAP_OPT_API_INFO" 
+	     "LDAP_OPT_DEREF" 
+	     "LDAP_OPT_SIZELIMIT"
+	     "LDAP_OPT_TIMELIMIT"
+	     "LDAP_OPT_REFERRALS"
+	     "LDAP_OPT_RESTART"
+	     "LDAP_OPT_PROTOCOL_VERSION"
+	     "LDAP_OPT_SERVER_CONTROLS"
+	     "LDAP_OPT_CLIENT_CONTROLS"
+	     "LDAP_OPT_API_FEATURE_INFO"
+	     "LDAP_OPT_HOST_NAME"
+	     "LDAP_OPT_ERROR_NUMBER"
+	     "LDAP_OPT_ERROR_STRING"
+	     "LDAP_OPT_MATCHED_DN")))
+
+    (define ldap-attribute-selectors
+      (list
+       (make-string-constant 
+	"LDAP_NO_ATTRS" "ldap-attributes-no-attribute")
+       (make-string-constant 
+	"LDAP_ALL_USER_ATTRIBUTES" "ldap-attributes-all-user-attributes")))
+
     (define ldap-all-constants
       (append ldap-return-codes
-	      ldap-opt-protocol-version))
+	      ldap-opt-protocol-version
+	      ldap-scope-arguments
+	      ldap-attribute-selectors
+	      ldap-session-options))
 	   
     (define (write-source-file name string)
       (call-with-output-file name
@@ -105,12 +136,25 @@
       (write-source-file 
        (string-append path "/const-gen.scm")
        (string-append
+
 	(generate-finite-type-definition 
 	 "ldap-return" (make-drop-common-prefix-name-converter "LDAP_")
 	 ldap-return-codes)
+
 	(generate-finite-type-definition
 	 "ldap-option-version" (make-drop-common-prefix-name-converter "LDAP_")
-	 ldap-opt-protocol-version))))
+	 ldap-opt-protocol-version)
+
+	(generate-finite-type-definition
+	 "ldap-scope-arguments" (make-drop-common-prefix-name-converter "LDAP_SCOPE_")
+	 ldap-scope-arguments)
+
+	(generate-finite-type-definition
+	 "ldap-session-options" (make-drop-common-prefix-name-converter "LDAP_OPT_")
+	 ldap-session-options)
+
+	(string-join
+	 (map generate-binding ldap-attribute-selectors)))))
 
     (define (make-c-files args)
       (if (null? args)