diff --git a/Library/Homebrew/dev-cmd/unpack.rb b/Library/Homebrew/dev-cmd/unpack.rb
index 2fa824d422..fbdd7c459e 100644
--- a/Library/Homebrew/dev-cmd/unpack.rb
+++ b/Library/Homebrew/dev-cmd/unpack.rb
@@ -55,12 +55,13 @@ module Homebrew
 
       oh1 "Unpacking #{Formatter.identifier(f.full_name)} to: #{stage_dir}"
 
-      ENV["VERBOSE"] = "1" # show messages about tar
-      f.brew do
-        f.patch if args.patch?
-        cp_r getwd, stage_dir, preserve: true
+      # show messages about tar
+      with_env VERBOSE: "1" do
+        f.brew do
+          f.patch if args.patch?
+          cp_r getwd, stage_dir, preserve: true
+        end
       end
-      ENV["VERBOSE"] = nil
 
       next unless args.git?