diff --git a/bin/upload-to-s3 b/bin/upload-to-s3
index 4849c17fe..4bb04f747 100755
--- a/bin/upload-to-s3
+++ b/bin/upload-to-s3
@@ -34,7 +34,7 @@ main() {
         echo "Uploading $src → $dst"
         if [[ "$dst" == *.gz ]]; then
             gzip -c "$src"
-        elif  [[ "$dst" == *.xz ]]; then
+        elif  [[ "$src" != *.xz && "$dst" == *.xz ]]; then
             xz -2 -T0 -c "$src"
         else
             cat "$src"