diff --git a/nixos/modules/services/networking/stunnel.nix b/nixos/modules/services/networking/stunnel.nix
index 2720bcf10934..fe1616f411f0 100644
--- a/nixos/modules/services/networking/stunnel.nix
+++ b/nixos/modules/services/networking/stunnel.nix
@@ -16,8 +16,12 @@ let
   serverConfig = {
     options = {
       accept = mkOption {
-        type = types.int;
-        description = "On which port stunnel should listen for incoming TLS connections.";
+        type = types.either types.str types.int;
+        description = ''
+          On which [host:]port stunnel should listen for incoming TLS connections.
+          Note that unlike other softwares stunnel ipv6 address need no brackets,
+          so to listen on all IPv6 addresses on port 1234 one would use ':::1234'.
+        '';
       };
 
       connect = mkOption {