diff --git a/modules/programs/firefox/mkFirefoxModule.nix b/modules/programs/firefox/mkFirefoxModule.nix
index 831f59ddb..784114aac 100644
--- a/modules/programs/firefox/mkFirefoxModule.nix
+++ b/modules/programs/firefox/mkFirefoxModule.nix
@@ -207,6 +207,7 @@ let
       package.override (old: {
         cfg = old.cfg or { } // fcfg;
         extraPolicies = (old.extraPolicies or { }) // cfg.policies;
+        pkcs11Modules = (old.pkcs11Modules or [ ]) ++ cfg.pkcs11Modules;
       })
     else
       (pkgs.wrapFirefox.override { config = bcfg; }) package { };
@@ -782,6 +783,14 @@ in {
         `true`.
       '';
     };
+
+    pkcs11Modules = mkOption {
+      type = types.listOf types.package;
+      default = [ ];
+      description = ''
+        Additional packages to be loaded as PKCS #11 modules in Firefox.
+      '';
+    };
   };
 
   config = mkIf cfg.enable ({