diff --git a/lib/libdvbsub/dvbsubtitle.cpp b/lib/libdvbsub/dvbsubtitle.cpp
index d3384ccf7..26134b02d 100644
--- a/lib/libdvbsub/dvbsubtitle.cpp
+++ b/lib/libdvbsub/dvbsubtitle.cpp
@@ -200,8 +200,11 @@ cDvbSubtitleConverter::cDvbSubtitleConverter(void)
 
 cDvbSubtitleConverter::~cDvbSubtitleConverter()
 {
-	avcodec_close(avctx);
-	av_free(avctx);
+	if (avctx) {
+		avcodec_close(avctx);
+		av_free(avctx);
+		avctx = NULL;
+	}
 	delete bitmaps;
 }