diff --git a/libavcodec/lagarith.c b/libavcodec/lagarith.c
index b27e755a86..41df353b3a 100644
--- a/libavcodec/lagarith.c
+++ b/libavcodec/lagarith.c
@@ -496,7 +496,8 @@ static int lag_decode_frame(AVCodecContext *avctx,
         offset_ry += 4;
         offs[3] = AV_RL32(buf + 9);
     case FRAME_ARITH_RGB24:
-        if (frametype == FRAME_ARITH_RGB24)
+    case FRAME_U_RGB24:
+        if (frametype == FRAME_ARITH_RGB24 || frametype == FRAME_U_RGB24)
             avctx->pix_fmt = PIX_FMT_RGB24;
 
         if (avctx->get_buffer(avctx, p) < 0) {