diff --git a/libavcodec/libgsm.c b/libavcodec/libgsm.c
index 203e360375..919387492c 100644
--- a/libavcodec/libgsm.c
+++ b/libavcodec/libgsm.c
@@ -72,7 +72,6 @@ static av_cold int libgsm_encode_init(AVCodecContext *avctx) {
     }
 
     avctx->coded_frame= avcodec_alloc_frame();
-    avctx->coded_frame->key_frame= 1;
     if (!avctx->coded_frame)
         goto error;