diff --git a/install/tools/ipa-adtrust-install.in b/install/tools/ipa-adtrust-install.in
index 9cb89ea11..f245ab342 100644
--- a/install/tools/ipa-adtrust-install.in
+++ b/install/tools/ipa-adtrust-install.in
@@ -64,10 +64,11 @@ def parse_options():
     parser.add_option("--no-msdcs", dest="no_msdcs", action="store_true",
                       default=False, help=SUPPRESS_HELP)
 
-    parser.add_option("--rid-base", dest="rid_base", type=int, default=1000,
+    parser.add_option("--rid-base", dest="rid_base", type=int,
+                      default=adtrust.DEFAULT_PRIMARY_RID_BASE,
                       help="Start value for mapping UIDs and GIDs to RIDs")
     parser.add_option("--secondary-rid-base", dest="secondary_rid_base",
-                      type=int, default=100000000,
+                      type=int, default=adtrust.DEFAULT_SECONDARY_RID_BASE,
                       help="Start value of the secondary range for mapping "
                            "UIDs and GIDs to RIDs")
     parser.add_option("-U", "--unattended", dest="unattended",
diff --git a/ipaserver/install/adtrust.py b/ipaserver/install/adtrust.py
index c01748bc0..6eb6a25ee 100644
--- a/ipaserver/install/adtrust.py
+++ b/ipaserver/install/adtrust.py
@@ -39,6 +39,9 @@ logger = logging.getLogger(__name__)
 netbios_name = None
 reset_netbios_name = False
 
+DEFAULT_PRIMARY_RID_BASE = 1000
+DEFAULT_SECONDARY_RID_BASE = 100000000
+
 
 def netbios_name_error(name):
     logger.error("\nIllegal NetBIOS name [%s].\n", name)
@@ -553,12 +556,12 @@ class SIDInstallInterface(ServiceAdminInstallInterface):
     )
     rid_base = knob(
         int,
-        1000,
+        DEFAULT_PRIMARY_RID_BASE,
         description="Start value for mapping UIDs and GIDs to RIDs"
     )
     secondary_rid_base = knob(
         int,
-        100000000,
+        DEFAULT_SECONDARY_RID_BASE,
         description="Start value of the secondary range for mapping "
                     "UIDs and GIDs to RIDs"
     )