diff --git a/libavcodec/lclenc.c b/libavcodec/lclenc.c
index 201d357898..864adc9850 100644
--- a/libavcodec/lclenc.c
+++ b/libavcodec/lclenc.c
@@ -165,7 +165,7 @@ static av_cold int encode_init(AVCodecContext *avctx)
     zret = deflateInit(&c->zstream, c->compression);
     if (zret != Z_OK) {
         av_log(avctx, AV_LOG_ERROR, "Deflate init error: %d\n", zret);
-        return 1;
+        return AVERROR_UNKNOWN;
     }
 
     return 0;