diff --git a/libavcodec/fic.c b/libavcodec/fic.c
index 9453941b76..1dfa02d222 100644
--- a/libavcodec/fic.c
+++ b/libavcodec/fic.c
@@ -261,6 +261,7 @@ static int fic_decode_frame(AVCodecContext *avctx, void *data,
         av_log(avctx, AV_LOG_ERROR, "Could not allocate slice data.\n");
         return AVERROR(ENOMEM);
     }
+    memset(ctx->slice_data, 0, nslices * sizeof(ctx->slice_data[0]));
 
     for (slice = 0; slice < nslices; slice++) {
         unsigned slice_off = AV_RB32(src + tsize + FIC_HEADER_SIZE + slice * 4);