diff --git a/lib/rscons/environment.rb b/lib/rscons/environment.rb
index e7369ec..d2851b1 100644
--- a/lib/rscons/environment.rb
+++ b/lib/rscons/environment.rb
@@ -1,7 +1,6 @@
 require "fileutils"
 require "set"
 require "shellwords"
-require "thwait"
 
 module Rscons
   # The Environment class is the main programmatic interface to Rscons. It
@@ -702,10 +701,7 @@ module Rscons
           !thread.alive?
         end
       else
-        if @threads.empty?
-          raise "No threads to wait for"
-        end
-        ThreadsWait.new(*@threads.keys).next_wait
+        Util.wait_for_thread(*@threads.keys)
       end
     end
 
diff --git a/lib/rscons/util.rb b/lib/rscons/util.rb
index 256547b..2958424 100644
--- a/lib/rscons/util.rb
+++ b/lib/rscons/util.rb
@@ -191,6 +191,32 @@ module Rscons
         deps
       end
 
+      # Wait for any of a number of threads to complete.
+      #
+      # @param threads [Array<Thread>]
+      #   Threads to wait for.
+      #
+      # @return [Thread]
+      #   The Thread that completed.
+      def wait_for_thread(*threads)
+        if threads.empty?
+          raise "No threads to wait for"
+        end
+        queue = Queue.new
+        threads.each do |thread|
+          # Create a wait thread for each thread we're waiting for.
+          Thread.new do
+            begin
+              thread.join
+            ensure
+              queue.push(thread)
+            end
+          end
+        end
+        # Wait for any thread to complete.
+        queue.pop
+      end
+
       private
 
       # Check if a directory contains a certain executable.
diff --git a/spec/build_tests_spec.rb b/spec/build_tests_spec.rb
index a8389e2..31656f4 100644
--- a/spec/build_tests_spec.rb
+++ b/spec/build_tests_spec.rb
@@ -143,7 +143,7 @@ EOF
       end
     end
     stdout, stderr, status = nil, nil, nil
-    Bundler.with_clean_env do
+    Bundler.with_unbundled_env do
       env = ENV.to_h
       path = ["#{@build_test_run_dir}/_bin", "#{env["PATH"]}"]
       if options[:path]