diff --git a/tests/expression/1.0/Android.bp b/tests/expression/1.0/Android.bp
new file mode 100644
index 0000000..32d4682
--- /dev/null
+++ b/tests/expression/1.0/Android.bp
@@ -0,0 +1,50 @@
+// This file is autogenerated by hidl-gen. Do not edit manually.
+
+genrule {
+    name: "android.hardware.tests.expression@1.0_genc++",
+    tool: "hidl-gen",
+    cmd: "$tool -o $genDir -Lc++ -randroid.hardware:hardware/interfaces android.hardware.tests.expression@1.0",
+    srcs: [
+        "IExpression.hal",
+        "IExpressionExt.hal",
+    ],
+    out: [
+        "android/hardware/tests/expression/1.0/ExpressionAll.cpp",
+        "android/hardware/tests/expression/1.0/ExpressionExtAll.cpp",
+    ],
+}
+
+genrule {
+    name: "android.hardware.tests.expression@1.0_genc++_headers",
+    tool: "hidl-gen",
+    cmd: "$tool -o $genDir -Lc++ -randroid.hardware:hardware/interfaces android.hardware.tests.expression@1.0",
+    srcs: [
+        "IExpression.hal",
+        "IExpressionExt.hal",
+    ],
+    out: [
+        "android/hardware/tests/expression/1.0/IExpression.h",
+        "android/hardware/tests/expression/1.0/IHwExpression.h",
+        "android/hardware/tests/expression/1.0/BnExpression.h",
+        "android/hardware/tests/expression/1.0/BpExpression.h",
+        "android/hardware/tests/expression/1.0/BsExpression.h",
+        "android/hardware/tests/expression/1.0/IExpressionExt.h",
+        "android/hardware/tests/expression/1.0/IHwExpressionExt.h",
+        "android/hardware/tests/expression/1.0/BnExpressionExt.h",
+        "android/hardware/tests/expression/1.0/BpExpressionExt.h",
+        "android/hardware/tests/expression/1.0/BsExpressionExt.h",
+    ],
+}
+
+cc_library_shared {
+    name: "android.hardware.tests.expression@1.0",
+    generated_sources: ["android.hardware.tests.expression@1.0_genc++"],
+    generated_headers: ["android.hardware.tests.expression@1.0_genc++_headers"],
+    export_generated_headers: ["android.hardware.tests.expression@1.0_genc++_headers"],
+    shared_libs: [
+        "libhidl",
+        "libhwbinder",
+        "libutils",
+        "libcutils",
+    ],
+}
diff --git a/tests/expression/1.0/Android.mk b/tests/expression/1.0/Android.mk
index 804af71..dbb97dc 100644
--- a/tests/expression/1.0/Android.mk
+++ b/tests/expression/1.0/Android.mk
@@ -1,58 +1,6 @@
+# This file is autogenerated by hidl-gen. Do not edit manually.
+
 LOCAL_PATH := $(call my-dir)
-include $(CLEAR_VARS)
-
-LOCAL_MODULE := android.hardware.tests.expression@1.0
-LOCAL_MODULE_CLASS := SHARED_LIBRARIES
-
-intermediates := $(local-generated-sources-dir)
-
-HIDL := $(HOST_OUT_EXECUTABLES)/hidl-gen$(HOST_EXECUTABLE_SUFFIX)
-
-#
-# Build IExpression.hal
-#
-GEN := $(intermediates)/android/hardware/tests/expression/1.0/ExpressionAll.cpp
-$(GEN): $(HIDL)
-$(GEN): PRIVATE_HIDL := $(HIDL)
-$(GEN): PRIVATE_DEPS := $(LOCAL_PATH)/IExpression.hal
-$(GEN): PRIVATE_OUTPUT_DIR := $(intermediates)
-$(GEN): PRIVATE_CUSTOM_TOOL = \
-        $(PRIVATE_HIDL) -o $(PRIVATE_OUTPUT_DIR) \
-        -Lc++ -randroid.hardware:hardware/interfaces \
-        android.hardware.tests.expression@1.0::IExpression
-
-$(GEN): $(LOCAL_PATH)/IExpression.hal
-	$(transform-generated-source)
-LOCAL_GENERATED_SOURCES += $(GEN)
-
-#
-# Build IExpressionExt.hal
-#
-GEN := $(intermediates)/android/hardware/tests/expression/1.0/ExpressionExtAll.cpp
-$(GEN): $(HIDL)
-$(GEN): PRIVATE_HIDL := $(HIDL)
-$(GEN): PRIVATE_DEPS := $(LOCAL_PATH)/IExpressionExt.hal
-$(GEN): PRIVATE_DEPS += $(LOCAL_PATH)/IExpression.hal
-$(GEN): $(LOCAL_PATH)/IExpression.hal
-$(GEN): PRIVATE_OUTPUT_DIR := $(intermediates)
-$(GEN): PRIVATE_CUSTOM_TOOL = \
-        $(PRIVATE_HIDL) -o $(PRIVATE_OUTPUT_DIR) \
-        -Lc++ -randroid.hardware:hardware/interfaces \
-        android.hardware.tests.expression@1.0::IExpressionExt
-
-$(GEN): $(LOCAL_PATH)/IExpressionExt.hal
-	$(transform-generated-source)
-LOCAL_GENERATED_SOURCES += $(GEN)
-
-LOCAL_EXPORT_C_INCLUDE_DIRS := $(intermediates)
-LOCAL_SHARED_LIBRARIES := \
-    libhidl \
-    libhwbinder \
-    libutils \
-    libcutils \
-
-LOCAL_MULTILIB := both
-include $(BUILD_SHARED_LIBRARY)
 
 ################################################################################