diff --git a/arm64v8.dockerfile b/arm64v8.dockerfile
index 1083acb..b4acbea 100644
--- a/arm64v8.dockerfile
+++ b/arm64v8.dockerfile
@@ -37,6 +37,7 @@ ENV SMA_PATH /usr/local/sma
 ENV youtubeSubtitleLanguage=en
 ENV enableAudioScript=true
 ENV enableVideoScript=true
+ENV matchDistance=5
 
 RUN \
 	echo "*** install packages ***" && \