diff --git a/virtweb_backend/src/utils/net_utils.rs b/virtweb_backend/src/utils/net_utils.rs
index d9bf679..e5cffe9 100644
--- a/virtweb_backend/src/utils/net_utils.rs
+++ b/virtweb_backend/src/utils/net_utils.rs
@@ -32,7 +32,7 @@ pub fn is_ipv4_mask_valid(mask: u8) -> bool {
 }
 
 pub fn is_ipv6_mask_valid(mask: u8) -> bool {
-    mask <= 64
+    mask <= 128
 }
 
 pub fn is_mask_valid(ipv: usize, mask: u8) -> bool {
@@ -79,6 +79,7 @@ mod tests {
         assert!(is_ipv6_address_valid("fe80::"));
         assert!(is_ipv6_address_valid("fe80:dd::"));
         assert!(is_ipv6_address_valid("00:00:00:00:00::"));
+        assert!(is_ipv6_address_valid("0:0:0:0:0:0:0:0"));
 
         assert!(!is_ipv6_address_valid("tata"));
         assert!(!is_ipv6_address_valid("2.56.58.156"));
@@ -93,6 +94,8 @@ mod tests {
         assert!(is_mask_valid(6, 34));
 
         assert!(!is_mask_valid(4, 34));
-        assert!(!is_mask_valid(6, 69));
+        assert!(is_mask_valid(6, 69));
+        assert!(is_mask_valid(6, 128));
+        assert!(!is_mask_valid(6, 129));
     }
 }
diff --git a/virtweb_frontend/src/widgets/forms/IPInput.tsx b/virtweb_frontend/src/widgets/forms/IPInput.tsx
index c497e7a..c7db678 100644
--- a/virtweb_frontend/src/widgets/forms/IPInput.tsx
+++ b/virtweb_frontend/src/widgets/forms/IPInput.tsx
@@ -128,6 +128,6 @@ function sanitizeMask(version: 4 | 6, mask?: string): number | undefined {
   if (version === 4) {
     return value < 0 || value > 32 ? 32 : value;
   } else {
-    return value < 0 || value > 64 ? 64 : value;
+    return value < 0 || value > 128 ? 128 : value;
   }
 }