diff --git a/nixos/modules/services/misc/matrix-synapse.nix b/nixos/modules/services/misc/matrix-synapse.nix
index 0f4eb2ccfcad4c..50661b873f64c0 100644
--- a/nixos/modules/services/misc/matrix-synapse.nix
+++ b/nixos/modules/services/misc/matrix-synapse.nix
@@ -407,6 +407,9 @@ in {
           "192.168.0.0/16"
           "100.64.0.0/10"
           "169.254.0.0/16"
+          "::1/128"
+          "fe80::/64"
+          "fc00::/7"
         ];
         description = ''
           List of IP address CIDR ranges that the URL preview spider is denied