diff --git a/src/h264.c b/src/h264.c
index fb6c13a..353cfa0 100644
--- a/src/h264.c
+++ b/src/h264.c
@@ -559,8 +559,24 @@ int h264_set_controls(struct request_data *driver_data,
 		}
 	};
 
+	/*
+	 * PRED_WEIGHTS is conditionally required per kernel UAPI:
+	 * V4L2_H264_CTRL_PRED_WEIGHTS_REQUIRED(pps, slice) is only
+	 * true when explicit weighted prediction applies (P/SP slice
+	 * with WEIGHTED_PRED flag, or B slice with weighted_bipred_idc
+	 * == 1). Submitting it unconditionally on a frame that does
+	 * not need it triggers EINVAL at error_idx=5 on hantro and
+	 * other drivers that strictly enforce the spec.
+	 *
+	 * controls[5] is PRED_WEIGHTS (last in array); narrow the
+	 * submission count to exclude it when not required.
+	 */
+	unsigned int num_controls = 6;
+	if (!V4L2_H264_CTRL_PRED_WEIGHTS_REQUIRED(&pps, &slice))
+		num_controls = 5;
+
 	rc = v4l2_set_controls(driver_data->video_fd, surface->request_fd,
-			       controls, 6);
+			       controls, num_controls);
 	if (rc < 0)
 		return VA_STATUS_ERROR_OPERATION_FAILED;