diff --git a/libavcodec/libcelt_dec.c b/libavcodec/libcelt_dec.c
index 6f3965401c..32948e3aec 100644
--- a/libavcodec/libcelt_dec.c
+++ b/libavcodec/libcelt_dec.c
@@ -91,6 +91,7 @@ static av_cold int libcelt_dec_init(AVCodecContext *c)
                    "improperly decoded by libcelt for version 0x%x.\n",
                    version, lib_version);
     }
+    c->sample_fmt = AV_SAMPLE_FMT_S16;
     return 0;
 }