diff --git a/netbox/ipam/forms.py b/netbox/ipam/forms.py
index f1e55ef25..35cf12dfb 100644
--- a/netbox/ipam/forms.py
+++ b/netbox/ipam/forms.py
@@ -18,8 +18,13 @@ from .choices import *
 from .models import Aggregate, IPAddress, Prefix, RIR, Role, Service, VLAN, VLANGroup, VRF
 
 
-PREFIX_MASK_LENGTH_CHOICES = add_blank_choice([(i, i) for i in range(1, 128)])
-IPADDRESS_MASK_LENGTH_CHOICES = add_blank_choice([(i, i) for i in range(1, 129)])
+PREFIX_MASK_LENGTH_CHOICES = add_blank_choice([
+    (i, i) for i in range(PREFIX_LENGTH_MIN, PREFIX_LENGTH_MAX + 1)
+])
+
+IPADDRESS_MASK_LENGTH_CHOICES = add_blank_choice([
+    (i, i) for i in range(IPADDRESS_MASK_LENGTH_MIN, IPADDRESS_MASK_LENGTH_MAX + 1)
+])
 
 
 #