diff --git a/build_tests/simple/build_sources.rb b/build_tests/simple/build_sources.rb
new file mode 100644
index 0000000..3db4ac5
--- /dev/null
+++ b/build_tests/simple/build_sources.rb
@@ -0,0 +1,14 @@
+class MyProgram < Rscons::Builder
+  def run(options)
+    target, sources, cache, env, vars = options.values_at(:target, :sources, :cache, :env, :vars)
+    objects = env.build_sources(sources, [".o"], cache, vars)
+    command = %W[gcc -o #{target}] + objects
+    return false unless env.execute("#{name} #{target}", command)
+    target
+  end
+end
+
+Rscons::Environment.new do |env|
+  env.add_builder(MyProgram.new)
+  env.MyProgram("simple.exe", "simple.c")
+end
diff --git a/spec/build_tests_spec.rb b/spec/build_tests_spec.rb
index 269d401..74a24a7 100644
--- a/spec/build_tests_spec.rb
+++ b/spec/build_tests_spec.rb
@@ -641,6 +641,16 @@ EOF
     ]
   end
 
+  it "allows a builder to call Environment#build_sources in a non-threaded manner" do
+    test_dir("simple")
+    result = run_test(rsconsfile: "build_sources.rb")
+    expect(result.stderr).to eq ""
+    expect(lines(result.stdout)).to eq [
+      "CC simple.o",
+      "MyProgram simple.exe",
+    ]
+  end
+
   context "Directory builder" do
     it "creates the requested directory" do
       test_dir("simple")