diff --git a/japanpost/gen.sh b/japanpost/gen.sh
index 153b0b046..f5061161b 100755
--- a/japanpost/gen.sh
+++ b/japanpost/gen.sh
@@ -33,4 +33,7 @@ rm -rf "$TARGET_DIR" && tar -xzf "$WORK_DIR/jp.tar.gz" -C "$WORK_DIR"
 
 ## Pack with a relative path so the archive stays rooted at jp/ (s3_sync.sh
 ## extracts it and runs `aws s3 sync jp/`, which needs a top-level jp/ entry).
-tar -C "$WORK_DIR" -czf "$WORK_DIR/jp.tar.gz" jp
+## COPYFILE_DISABLE=1 stops macOS tar from adding AppleDouble (._*) members and
+## xattr headers; otherwise GNU tar on Linux extracts the ._* files and they get
+## synced to S3 as junk (doubling the upload).
+COPYFILE_DISABLE=1 tar -C "$WORK_DIR" -czf "$WORK_DIR/jp.tar.gz" jp
diff --git a/jp.tar.gz b/jp.tar.gz
index 4a1267619..5732d4246 100644
Binary files a/jp.tar.gz and b/jp.tar.gz differ
diff --git a/s3_sync.sh b/s3_sync.sh
index 850ed838b..07fc0db23 100755
--- a/s3_sync.sh
+++ b/s3_sync.sh
@@ -9,4 +9,4 @@ fi;
 echo "BUCKET $BUCKET"
 echo "COUNTRY $COUNTRY"
 
-tar -xzf ./$COUNTRY.tar.gz && aws s3 sync $COUNTRY/ s3://$BUCKET/$COUNTRY/ --exclude "*" --include "*.json"
+tar -xzf ./$COUNTRY.tar.gz && aws s3 sync $COUNTRY/ s3://$BUCKET/$COUNTRY/ --exclude "*" --include "*.json" --exclude "._*"