diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 908dedf097f4..7bcba4f1ee1c 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -1809,6 +1809,9 @@ static int vc4_hdmi_encoder_atomic_check(struct drm_encoder *encoder,
 	struct vc4_hdmi_connector_state *vc4_state = conn_state_to_vc4_hdmi_conn_state(conn_state);
 	struct drm_display_mode *mode = &crtc_state->adjusted_mode;
 	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
+	struct drm_connector *connector = &vc4_hdmi->connector;
+	struct drm_connector_state *old_conn_state = drm_atomic_get_old_connector_state(conn_state->state, connector);
+	struct vc4_hdmi_connector_state *old_vc4_state = conn_state_to_vc4_hdmi_conn_state(old_conn_state);
 	unsigned long long pixel_rate = mode->clock * 1000;
 	unsigned long long tmds_rate;
 	int ret;
@@ -1837,6 +1840,11 @@ static int vc4_hdmi_encoder_atomic_check(struct drm_encoder *encoder,
 	if (ret)
 		return ret;
 
+	/* vc4_hdmi_encoder_compute_config may have changed output_bpc and/or output_format */
+	if (vc4_state->output_bpc != old_vc4_state->output_bpc ||
+	    vc4_state->output_format != old_vc4_state->output_format)
+		crtc_state->mode_changed = true;
+
 	return 0;
 }