diff --git a/tool/make-snapshot b/tool/make-snapshot
index 9199cc2097..8ce14214ba 100755
--- a/tool/make-snapshot
+++ b/tool/make-snapshot
@@ -58,8 +58,7 @@ PACKAGES = {
 if system("7z", out: IO::NULL)
   PACKAGES["gzip"] = %w".tar.gz 7z a dummy -tgzip -mx -so"
   PACKAGES["zip"]  = %w".zip    7z a -tzip  -mx" << {out: IO::NULL}
-end
-if gzip = ENV.delete("GZIP")
+elsif gzip = ENV.delete("GZIP")
   PACKAGES["gzip"].concat(gzip.shellsplit)
 end