diff --git a/patches/004-h264-passthrough.patch b/patches/004-h264-passthrough.patch
index aa10297..94a579c 100644
--- a/patches/004-h264-passthrough.patch
+++ b/patches/004-h264-passthrough.patch
@@ -992,7 +992,7 @@ index 327e7c2b..c49737d7 100644
  /**
   * Callback which associates handlers specific to Guacamole with the
   * RdpgfxClientContext instance allocated by FreeRDP to deal with received
-@@ -63,13 +438,45 @@ static void guac_rdp_rdpgfx_channel_connected(rdpContext* context,
+@@ -63,13 +438,68 @@ static void guac_rdp_rdpgfx_channel_connected(rdpContext* context,
      RdpgfxClientContext* rdpgfx = (RdpgfxClientContext*) args->pInterface;
      rdpGdi* gdi = context->gdi;
  
@@ -1009,27 +1009,50 @@ index 327e7c2b..c49737d7 100644
 +        guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
 +
 +        /* Installed only for a connection that asked for H.264, and only
-+         * once. This handler runs again whenever the RDPGFX channel
-+         * reconnects -- the display resize xrdp performs at login triggers
-+         * exactly that -- and a second install reads back the wrapper the
-+         * first one left behind, so orig_surface_command ends up pointing at
-+         * guac_rdp_gfx_surface_command itself. Every surface command that is
-+         * not H.264 then calls the wrapper from inside the wrapper and
-+         * recurses until the stack is gone. H.264 commands take the
++         * onto a handler that is not already ours. This runs again every
++         * time the RDPGFX channel reconnects -- the display resize xrdp
++         * performs at login triggers exactly that -- and the two ways of
++         * getting it wrong fail in opposite directions.
++         *
++         * Reinstalling unconditionally is fatal: the second pass reads back
++         * the wrapper the first one left, orig_surface_command ends up
++         * pointing at guac_rdp_gfx_surface_command itself, and every surface
++         * command that is not H.264 calls the wrapper from inside the
++         * wrapper until the stack is gone. H.264 commands take the
 +         * skip_decode path and never make that call, so a server sending
-+         * nothing but H.264 survives it, while one mixing in planar or
-+         * progressive surfaces dies on the first of them. */
-+        if (rdp_client->settings->enable_h264
-+                && rdp_client->orig_surface_command == NULL) {
++         * nothing but H.264 survives it while one mixing in planar or
++         * progressive surfaces dies on the first of them.
++         *
++         * Installing only once is quieter and just as broken.
++         * gdi_graphics_pipeline_uninit() sets SurfaceCommand to NULL and
++         * gdi_graphics_pipeline_init() puts gdi_SurfaceCommand back, so a
++         * reconnect leaves FreeRDP's own handler installed while a
++         * once-only guard declines to wrap it again. Passthrough then stops
++         * for the rest of the session -- silently, since the frames still
++         * render via GDI and guacd simply re-encodes them.
++         *
++         * Testing what is actually installed, per callback, covers both. */
++        if (rdp_client->settings->enable_h264) {
 +
 +            /* Wrap SurfaceCommand to intercept H.264 data after GDI decode.
 +             * Store the original callback per-connection to avoid clobbering
 +             * when multiple RDP sessions are active concurrently. */
-+            rdp_client->orig_surface_command = (void*) rdpgfx->SurfaceCommand;
-+            rdpgfx->SurfaceCommand = guac_rdp_gfx_surface_command;
++            if (rdpgfx->SurfaceCommand != guac_rdp_gfx_surface_command) {
++                rdp_client->orig_surface_command = (void*) rdpgfx->SurfaceCommand;
++                rdpgfx->SurfaceCommand = guac_rdp_gfx_surface_command;
++            }
 +
-+            rdp_client->orig_caps_confirm = (void*) rdpgfx->CapsConfirm;
-+            rdpgfx->CapsConfirm = guac_rdp_gfx_caps_confirm;
++            /* Guarded separately, because the two callbacks are restored on
++             * different schedules: gdi_graphics_pipeline_init() assigns
++             * SurfaceCommand but never touches CapsConfirm, so after a
++             * reconnect CapsConfirm is still ours while SurfaceCommand is
++             * FreeRDP's again. One shared guard therefore re-reads a wrapper
++             * we installed ourselves and points orig_caps_confirm at
++             * guac_rdp_gfx_caps_confirm. */
++            if (rdpgfx->CapsConfirm != guac_rdp_gfx_caps_confirm) {
++                rdp_client->orig_caps_confirm = (void*) rdpgfx->CapsConfirm;
++                rdpgfx->CapsConfirm = guac_rdp_gfx_caps_confirm;
++            }
 +
 +            guac_client_log(client, GUAC_LOG_INFO,
 +                    "H.264 passthrough enabled for RDPGFX channel.");