diff --git a/dexpreopt/testing.go b/dexpreopt/testing.go
new file mode 100644
index 0000000..b572eb3
--- /dev/null
+++ b/dexpreopt/testing.go
@@ -0,0 +1,47 @@
+// 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 dexpreopt
+
+import (
+	"android/soong/android"
+)
+
+type dummyToolBinary struct {
+	android.ModuleBase
+}
+
+func (m *dummyToolBinary) GenerateAndroidBuildActions(ctx android.ModuleContext) {}
+
+func (m *dummyToolBinary) HostToolPath() android.OptionalPath {
+	return android.OptionalPathForPath(android.PathForTesting("dex2oat"))
+}
+
+func dummyToolBinaryFactory() android.Module {
+	module := &dummyToolBinary{}
+	android.InitAndroidArchModule(module, android.HostSupported, android.MultilibFirst)
+	return module
+}
+
+func RegisterToolModulesForTest(ctx *android.TestContext) {
+	ctx.RegisterModuleType("dummy_tool_binary", dummyToolBinaryFactory)
+}
+
+func BpToolModulesForTest() string {
+	return `
+		dummy_tool_binary {
+			name: "dex2oatd",
+		}
+	`
+}