diff --git a/hosts/12kingdoms-youko/homelab-services/jellyfin.nix b/hosts/12kingdoms-youko/homelab-services/jellyfin.nix
index c60bf8fd..ad621c3c 100644
--- a/hosts/12kingdoms-youko/homelab-services/jellyfin.nix
+++ b/hosts/12kingdoms-youko/homelab-services/jellyfin.nix
@@ -27,6 +27,14 @@ in
   # (and therefore VA-API) is missing.
   hardware.graphics.enable = true;
 
+  # HDR/DoVi transcoding needs OpenCL for `tonemap_opencl`. With only Mesa
+  # installed, ffmpeg cannot create an OpenCL device (`Failed to get number of
+  # OpenCL platforms: -1001`) and the transcode aborts with exit code 237, so
+  # HDR titles fail to play. ROCm's clr provides the ICD for the Barceló iGPU
+  # (reported as `gfx90c`); `ocl-icd` finds it under
+  # /run/opengl-driver/etc/OpenCL/vendors.
+  hardware.graphics.extraPackages = [ pkgs.rocmPackages.clr.icd ];
+
   services.jellyfin = {
     enable = true;
 
@@ -96,4 +104,11 @@ in
   # before it is mounted. The module's own RequiresMountsFor entries for
   # config/log/cache are merged with these list definitions.
   systemd.services.jellyfin.unitConfig.RequiresMountsFor = [ mediaDir ];
+
+  # ROCm's OpenCL runtime (used for HDR tone mapping via `tonemap_opencl`)
+  # reaches the GPU through /dev/kfd. The module's device whitelist only allows
+  # the VA-API render node, so OpenCL init fails and HDR transcodes abort with
+  # exit code 237. Allow the compute node too (list definitions merge with the
+  # module's entry).
+  systemd.services.jellyfin.serviceConfig.DeviceAllow = [ "/dev/kfd rw" ];
 }