diff --git a/Library/Homebrew/unpack_strategy.rb b/Library/Homebrew/unpack_strategy.rb
index 9ce91d8582..b18dde19a5 100644
--- a/Library/Homebrew/unpack_strategy.rb
+++ b/Library/Homebrew/unpack_strategy.rb
@@ -129,6 +129,8 @@ module UnpackStrategy
       children = tmp_unpack_dir.children
 
       if children.count == 1 && !children.first.directory?
+        FileUtils.chmod "+rw", children.first, verbose: verbose
+
         s = UnpackStrategy.detect(children.first, extension_only: extension_only)
 
         s.extract_nestedly(to: to, verbose: verbose, extension_only: extension_only)