diff --git a/modules/programs/firefox.nix b/modules/programs/firefox.nix
index 1370d4c28..78211df99 100644
--- a/modules/programs/firefox.nix
+++ b/modules/programs/firefox.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 { };
@@ -707,6 +708,14 @@ in {
           `true`.
         '';
       };
+
+      pkcs11Modules = mkOption {
+        type = types.listOf types.package;
+        default = [ ];
+        description = ''
+          Additional packages to be loaded as PKCS #11 modules in Firefox.
+        '';
+      };
     };
   };