diff --git a/nixos/modules/services/matrix/appservice-irc.nix b/nixos/modules/services/matrix/appservice-irc.nix
index df12998ab156..ac8d4250b9ac 100644
--- a/nixos/modules/services/matrix/appservice-irc.nix
+++ b/nixos/modules/services/matrix/appservice-irc.nix
@@ -147,10 +147,13 @@ in {
                     '';
                   };
                   ttlSeconds = lib.mkOption {
-                    type = ints.positive;
+                    type = ints.unsigned;
                     default = 3600;
+                    example = 0;
                     description = ''
                       Lifetime in seconds, that generated URLs stay valid.
+
+                      Set the lifetime to 0 to prevent URLs from becoming invalid.
                     '';
                   };
                   bindPort = lib.mkOption {
diff --git a/nixos/tests/matrix/appservice-irc.nix b/nixos/tests/matrix/appservice-irc.nix
index 2c556ec37fc5..41a6b005064f 100644
--- a/nixos/tests/matrix/appservice-irc.nix
+++ b/nixos/tests/matrix/appservice-irc.nix
@@ -84,7 +84,10 @@
                   aliasTemplate = "#irc_$CHANNEL";
                 };
               };
-              mediaProxy.publicUrl = "http://localhost:11111/media";
+              mediaProxy = {
+                publicUrl = "http://localhost:11111/media";
+                ttl = 0;
+              };
             };
           };
         };