diff --git a/ui/build/cleanbuild_test.go b/ui/build/cleanbuild_test.go
new file mode 100644
index 0000000..89f4ad9
--- /dev/null
+++ b/ui/build/cleanbuild_test.go
@@ -0,0 +1,100 @@
+// Copyright 2020 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package build
+
+import (
+	"android/soong/ui/logger"
+	"bytes"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"reflect"
+	"sort"
+	"strings"
+	"testing"
+)
+
+func TestCleanOldFiles(t *testing.T) {
+	dir, err := ioutil.TempDir("", "testcleanoldfiles")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	ctx := testContext()
+	logBuf := &bytes.Buffer{}
+	ctx.Logger = logger.New(logBuf)
+
+	touch := func(names ...string) {
+		for _, name := range names {
+			if f, err := os.Create(filepath.Join(dir, name)); err != nil {
+				t.Fatal(err)
+			} else {
+				f.Close()
+			}
+		}
+	}
+	runCleanOldFiles := func(names ...string) {
+		data := []byte(strings.Join(names, " "))
+		if err := ioutil.WriteFile(filepath.Join(dir, ".installed"), data, 0666); err != nil {
+			t.Fatal(err)
+		}
+
+		cleanOldFiles(ctx, dir, ".installed")
+	}
+
+	assertFileList := func(names ...string) {
+		t.Helper()
+
+		sort.Strings(names)
+
+		var foundNames []string
+		if foundFiles, err := ioutil.ReadDir(dir); err == nil {
+			for _, fi := range foundFiles {
+				foundNames = append(foundNames, fi.Name())
+			}
+		} else {
+			t.Fatal(err)
+		}
+
+		if !reflect.DeepEqual(names, foundNames) {
+			t.Errorf("Expected a different list of files:\nwant: %v\n got: %v", names, foundNames)
+			t.Error("Log: ", logBuf.String())
+			logBuf.Reset()
+		}
+	}
+
+	// Initial list of potential files
+	runCleanOldFiles("foo", "bar")
+	touch("foo", "bar", "baz")
+	assertFileList("foo", "bar", "baz", ".installed.previous")
+
+	// This should be a no-op, as the list hasn't changed
+	runCleanOldFiles("foo", "bar")
+	assertFileList("foo", "bar", "baz", ".installed", ".installed.previous")
+
+	// This should be a no-op, as only a file was added
+	runCleanOldFiles("foo", "bar", "foo2")
+	assertFileList("foo", "bar", "baz", ".installed.previous")
+
+	// "bar" should be removed, foo2 should be ignored as it was never there
+	runCleanOldFiles("foo")
+	assertFileList("foo", "baz", ".installed.previous")
+
+	// Recreate bar, and create foo2. Ensure that they aren't removed
+	touch("bar", "foo2")
+	runCleanOldFiles("foo", "baz")
+	assertFileList("foo", "bar", "baz", "foo2", ".installed.previous")
+}